Page 1 Agilent J-BERT N4903B High-Performance Serial BERT User Guide Agilent Technologies...
Page 2 Notices © Agilent Technologies, Inc. 2014 Manual Part Number agency regulation or contract clause. Use, duplication or disclosure of Software is No part of this manual may be reproduced in N4903-91021 subject to Agilent Technologies' standard any form or by any means (including...
Page 3: Table Of Contents
User Patterns - Procedures User Patterns - Reference Software-Generated PRBS Software-Generated PRBS - Concepts Software-Generated PRBS - Procedures Software-Generated PRBS - Reference Hardware-Generated PRBS Hardware-Generated PRBS - Concepts Hardware-Generated PRBS - Procedures Hardware-Generated PRBS - Reference Agilent J-BERT N4903B High-Performance Serial BERT...
Page 4 Delay Control Input - Procedures Delay Control Input - Reference Error Addition/Insertion Error Addition/Insertion - Concepts Error Addition/Insertion - Procedures Error Addition/Insertion - Reference Pattern Alternation Pattern Alternation - Concepts Pattern Alternation - Procedures Pattern Alternation - Reference Agilent J-BERT N4903B High-Performance Serial BERT...
Page 5 Error Accumulation - Procedures Error Accumulation - Reference BER Location BER Location - Concepts BER Location - Procedures BER Location - Reference Audio Signals Audio Signals - Concepts Audio Signals - Procedures Audio Signals - Reference Agilent J-BERT N4903B High-Performance Serial BERT...
Page 6 Spectral Jitter Spectral Jitter - Concepts Spectral Jitter - Procedures Spectral Jitter - Reference Evaluating Results Evaluating Results - Concepts Instantaneous Measurements Instantaneous Measurements - Concepts Instantaneous Measurements - Procedures Instantaneous Measurements - Reference Agilent J-BERT N4903B High-Performance Serial BERT...
Page 7 Jitter Tolerance Compliance - Reference Solving Problems Solving Problems - Concepts Setup Problems Setup Problems - Concepts Measurement Problems Measurement Problems - Concepts Other Messages Other Messages - Concepts N4916B System Setup Calibration N4916B System Setup Calibration Agilent J-BERT N4903B High-Performance Serial BERT...
Page 8 Installing External Instrument(s) Installing External Instrument(s) - Concepts Installing the N4916A/B - Procedure Installing the N4876A - Procedure Installing the M8061A - Procedure Installing Webserver Customizing the Web Server- Concept Printing Printing - Procedures Agilent J-BERT N4903B High-Performance Serial BERT...
Page 9 File Management File Management - Procedures Preset Instrument State Preset Instrument State - Procedures Self Test Self Test - Concepts Self Test - Procedures Self Test - Reference Index Agilent J-BERT N4903B High-Performance Serial BERT...
Page 10 Agilent J-BERT N4903B High-Performance Serial BERT...
Page 11: Planning The Test
Agilent J-BERT N4903B High-Performance Serial BERT User Guide Planning the Test Planning the Test - Concepts The following topics provide some information that can help you in planning tests with the Serial BERT: • “Introduction to the Serial BERT - Concepts ” on page 11 explains the basics of bit error rates (BER) and BER testing with the Serial BERT.
Page 12 BERs, and larger exponents correspond to lower BERs. Table 1 Fraction Exponent Instrument Display 1E+0 1 x 10 1/10 1E-1 1 x 10 1/100 1E-2 1 x 10 1/1000 1E-3 1 x 10 Agilent J-BERT N4903B High-Performance Serial BERT...
Page 13 1E-1 1 x 10 1/100 1E-2 1 x 10 1/1000 1E-3 1 x 10 1/10,000 1E-4 1 x 10 1/100,000 1E-5 1 x 10 1/1,000,000 1E-6 1 x 10 1/10,000,000 1E-7 1 x 10 Agilent J-BERT N4903B High-Performance Serial BERT...
Page 14 (CDR) • Bit rate range: 150 Mbit/s to 12.5 Gbit/s pattern generator and error detector with built-in CDR • A01, U01 Bit Recovery Mode (measures BER without expecting a particular pattern) • Agilent J-BERT N4903B High-Performance Serial BERT...
Page 15 About dialog shows the installed options. De-Emphasis Signal Converter An external optional instrument which is used to convert the output of the pattern generator to a de-emphasized signal, as required by many standards such as PCI Agilent J-BERT N4903B High-Performance Serial BERT...
Page 16 • Transparent to data jitter • Small size • Programmable via J-BERT N4903B or stand-alone • USB and LAN connectivity N4916B De-Emphasis Signal Converter The N4916B is a 4-tap de-emphasis signal converter with optional clock multiplier. It is intended to accurately characterize your multi-gigabit serial interfaces.
Page 17 M8061A 28 Gb/s Multiplexer with De-emphasis The Agilent's M8061A is a 2:1 multiplexer to characterize serial interfaces of up to 28.4 Gb/s with optional de-emphasis to extend the rate of J-BERT N4903B pattern generator. Data rates up to 28.4 Gb/s are used for: •...
Page 18: Navigating The Serial Bert Gui
Planning the Test • 2-slot AXIe module that can be controlled from J-BERT N4903B user interface via USB • Expands data rate of J-BERT N4903B pattern generator up to 28.4 Gb/s • Integrated and calibrated 4-tap de-emphasis, expandable to 8 taps •...
Page 19 No new errors: The triangle icon on the button will remain yellow. • Minimize Button: Minimizes the GUI to the Taskbar. • Remote Indicator: If the GUI is in remote state, the remote indicator turns blue and the mouse is catched within. Agilent J-BERT N4903B High-Performance Serial BERT...
Page 20 Warning indicators like Output Protection (Indicated by orange LED at the Outputs ON indicator). • Temperatur warnings (Only visible if the temperature exceeds a certain threshold value). For more information, see “Overheat Protection” on page 478. Agilent J-BERT N4903B High-Performance Serial BERT...
Page 21 Each group menu items has an image assigned to it. The image displayed on the menu item indicates the image of the last used control, which means, if you click somewhere on left of the seperator, it will directly open the last used control. Agilent J-BERT N4903B High-Performance Serial BERT...
Page 22 For more information on PG Setup, refer to the section “Setting up the Pattern Generator - Concepts ” on page 121. ED Setup The ED Setup menu allows you to launch the following controls: • Clock Setup • Error Ratio Agilent J-BERT N4903B High-Performance Serial BERT...
Page 23 Jitter Setup • Interference Channel • Jitter Tolerance Characterization • Jitter Tolerance Compliance • Generate HTML Report For more information on Jitter, refer to the section “Jitter Tolerance Tests - Concepts ” on page 395. Agilent J-BERT N4903B High-Performance Serial BERT...
Page 24 On... from the Help menu. This Help opens with information on the current Serial BERT window. • Switching to the Help Select Contents from the Help menu to switch to this Help. The last topic you visited is displayed. Agilent J-BERT N4903B High-Performance Serial BERT...
Page 25: Which Test Is Appropriate
Measurements - Concepts ” on page 376. • To measure the eye height and width of the incoming data signal at specific alignment BER thresholds. See “Eye Measurements - Concepts ” on page 392. Agilent J-BERT N4903B High-Performance Serial BERT...
Page 26 What termination voltage is the output of your device designed to work with? Make sure it is set for the error detector's data port termination. See “Data In Port Termination” on page 170. • What bit rate do you need to test your device at? Agilent J-BERT N4903B High-Performance Serial BERT...
Page 27 (155.52 Mb/s) (9.95328 Gb/ (2.48832 Gb/ (622.08 Mb/s) 1E-14 ~ 8.4 hours ~ 1.4 days ~ 5.6 days ~ 22.4 days 1E-13 ~ 50 minutes ~ 3.3 hours ~ 13 hours ~ 2.2 days Agilent J-BERT N4903B High-Performance Serial BERT...
Page 28 3 Calculate the number of bits n = - ln(1 - 0.95)/1E-10 = 2.99/1E-10 = 2.99E+10 bits 4 Calculate the time period at the STM-16/OC-48 bit rate (2.48832 Gb/s) 2.99E+10 / 2.48832E+9 = 12.016 seconds Agilent J-BERT N4903B High-Performance Serial BERT...
Page 29: Connecting The Dut
When making connections, ensure the proper use of a grounded, resistor-isolated wrist strap. Connect your device according to the diagrams below: Agilent J-BERT N4903B High-Performance Serial BERT...
Page 30 Often used for multiplexers, or when the data rate received by the device is not equal to the data rate sent from the device. Diagram 2. Connections for Differential Inputs Application is the same as in Diagram 1. Illustrates how to connect to a device requiring differential signals. Agilent J-BERT N4903B High-Performance Serial BERT...
Page 31 Planning the Test Diagram 3. Connections for an Amplifier Often used for amplifiers. Diagram 4. Connections for a Flip-Flop Often used for flip-flops. Agilent J-BERT N4903B High-Performance Serial BERT...
Page 32 Diagram 6. Connections for a DCA or Oscilloscope (PGonly) Used for measuring the output waveform of your device. For the least amount of jitter, the clock output signal may be used as a trigger for the oscilloscope. Agilent J-BERT N4903B High-Performance Serial BERT...
Page 33 Dynamic patterns and/or patterns with live payloads cannot be used. Diagrams 1 through 8 can use an external clock reference connected to the Clock N O T E In port of the pattern generator, if desired. Agilent J-BERT N4903B High-Performance Serial BERT...
Page 34 The unused output of the Pattern Generator has to be terminated with 50 Ohm. The N4876A provides a differential signal to the DUT. The N4876A is controlled by the Serial BERT via a USB cable connected to ports at the rear of the instruments. Agilent J-BERT N4903B High-Performance Serial BERT...
Page 35 The Data In 1, Data In 2 and Aux Clk In of M8061A have to be connected to Aux Data Out, Data Out and Aux Clk Out ports of the J-BERT N4903B, respectively. The connections should be made using the matched cable kit with the part number M8061-61601.
Page 36 Planning the Test Agilent J-BERT N4903B High-Performance Serial BERT...
Page 37: Setting Up External Instrument(S)
Agilent J-BERT N4903B High-Performance Serial BERT User Guide Setting up External Instrument(s) Setting up External Instrument(s) - Concepts The External Instrument(s) menu allows you to enable external instruments connected to Serial BERT through a user interface. Currently, the following external...
Page 38 They can considerably reduce the impact of Intersymbol Interference (ISI) and hence allow longer signal paths. De-emphasized signals are prescribed by a couple of popular standards for high-speed data transmission. Agilent J-BERT N4903B High-Performance Serial BERT...
Page 39 It is also possible to convert the input signal to a pre-cursor de-emphasized signal. Pre-cursor de-emphasis This can be done by setting the output voltage swing to the desired de-emphasis amplitude and specifying a negative amplitude ratio (an amplification). This inverts Agilent J-BERT N4903B High-Performance Serial BERT...
Page 40 The following example illustrates the output of the differential signal with variable De-emphasis on pre-cursor and 2 post- de-emphasis on pre-cursor and 2 post-cursors generated by De-Emphasis Signal cursors Converter N4916B. Agilent J-BERT N4903B High-Performance Serial BERT...
Page 41 N O T E Understanding the N4876A 28 Gb/s Multiplexer 2:1 The Agilent Technologies N4876A is a 2:1 multiplexer with an output data rate of up to 28.4 Gb/s. The N4876A multiplexer doubles the pattern generator data rate by multiplexing two pattern generator channels.
Page 42: Setting Up External Instrument(S) - Procedure
The Data In 1, Data In 2 and Aux Clk In of M8061A have to be connected to Aux Data Out, Data Out and Aux Clk Out ports of the J-BERT N4903B, respectively. The connections should be made using the matched cable kit with the part number M8061-61601.
Page 43 51. Here are few examples: Example - 1 The following image shows the Config window when the N4916B de-emphasis signal converter is connected to the J-BERT N4903B. Example - 2 The following image shows the Config window when the N4876A 28Gb/s Multiplexer is connected to the J-BERT N4903B.
Page 44 Setting up External Instrument(s) Example - 3 The following image shows the Config window when the M8061A 28Gb/s Multiplexer with De-emphasis is connected to the J-BERT N4903B. 2 Choose the external instrument from the instrument list shown on the Config window.
Page 45 N O T E able to see them in the instrument list. However, if the Config window still do not display any externally connected instruments, restart the J-BERT N4903B software and firmware. 3 Click Update button to update the software revision of external instrument (If required).
Page 46 3 To disable the de-emphasis function, clear the De-Emphasis function check box present on the Config window. It will disable the de-emphasis function and the respective parameters from the PG-Data Output screen also disappears. Agilent J-BERT N4903B High-Performance Serial BERT...
Page 47 3 To disable the Clock Multiplier function, clear the Clock Multiplier function check box present on the Config window. It will disable the clock multiplier function and the Clock Multiplier(DATAOUT) menu item disappears. How to Enable/Disable N4876A Multiplexer Function To enable/disable the multiplexer function: Agilent J-BERT N4903B High-Performance Serial BERT...
Page 48 External Instrument(s) sub-menu. 3 To disable the multiplexer function, clear the Multiplexer function check box present on the Config window. It will disable the multiplexer function and the Multiplexer (4876A) menu item disappears. Agilent J-BERT N4903B High-Performance Serial BERT...
Page 49 The following image shows the an example of M8061A. 2 Click Enable button. It enables multiplexer function that is connected between Data and Aux Data Output of J-BERT's Pattern Generator and the input of the M8061A. Agilent J-BERT N4903B High-Performance Serial BERT...
Page 50 “Track PG Clock Frequency” on page 2 If necessary, change the termination voltage by entering a new value. You can use the front panel knob to change the value. For more information, refer to the section “Termination” on page Agilent J-BERT N4903B High-Performance Serial BERT...
Page 51: Setting Up External Instrument(S) - Reference
“Electrical Idle In” on page Setting up External Instrument(s) - Reference Config Window The Config window provides an inferface which allows you to enable the functionality of the external instruments connected to the Serial BERT. Agilent J-BERT N4903B High-Performance Serial BERT...
Page 52 The connection type defines the connection. For example, if N4916B is connected Connection to the Data Out, it will show DATA_OUT. The Enable Function allows you to select and accordingly enable/disable the Enable Function selected functions provided by the externally connected instrument. The N4916A Agilent J-BERT N4903B High-Performance Serial BERT...
Page 53 For more information, refer to “Loading Calibration Settings” on page 480. The Adjustment has to be done once for a dedicated setup of J-BERT N4903B, Input Timing Adjustment M8061A/N4876A and the cable kit being used, whenever one of these components in the setup is changed, or if the operating temperature changes by more than 5 Celsius, compared to the previous adjustment.
Page 54 First it’s the data rate of the instrument (can be changed from the Pattern Generator – Bit Rate Setup dialog) and the Half Rate Clock check box (can be changed from the Pattern Generator Clock/Trigger Output). Agilent J-BERT N4903B High-Performance Serial BERT...
Page 55 The f/2 jitter defines how much 'mismatch' the period of odd/even bits at the f / 2 Jitter output of the MUX have. If f/2 jitter is at 0, then the observed output period at the multiplexer is half the input period. Agilent J-BERT N4903B High-Performance Serial BERT...
Page 56 M8061A Window The M8061A is a 2:1 multiplexer to characterize serial interfaces of up to 28.4 Gb/ s with optional de-emphasis to extend the rate of J-BERT N4903B pattern generator. The M8061A window is shown in the following figure. The M8061A window contains the following tabs: 1 DataOut Tab - provides parameters to set the amplifier, deemphasis and interference.
Page 57 CMI State: Used to enable/disable the Common Mode Interference. • CMI Gain: Used to set the Common Mode Interference Gain. • DMI State: Used to enable/disable the Differential Mode Interference. • DMI Gain: Used to set the Differential Mode Interference Gain. Agilent J-BERT N4903B High-Performance Serial BERT...
Page 58 -20 ps to 20 ps Termination Voltage -1 V to 3.3 V PreCursor2 -6.02 dB to 6.02 dB PreCursor1 -12.04 dB to 12.04 dB PostCursor1 -20 dB to 20 dB PostCursor2 -12.04 dB to 12.04 dB Agilent J-BERT N4903B High-Performance Serial BERT...
Page 59 Parameters Range PostCursor3 -12.04 dB to 12.04 dB PostCursor4 -6.02 dB to 6.02 dB PostCursor5 -6.02 dB to 6.02 dB Threshold Voltage -1 V to 3 V Termination Voltage -1 V to 3 V Agilent J-BERT N4903B High-Performance Serial BERT...
Page 60 Setting up External Instrument(s) Agilent J-BERT N4903B High-Performance Serial BERT...
Page 61: Setting Up Patterns
Agilent J-BERT N4903B High-Performance Serial BERT User Guide Setting up Patterns Setting up Patterns - Concepts The purpose of data patterns is to simulate the type of data that your device might receive in the real world. Different patterns present different data loads to your device, which can cause variations in the bit error ratio.
Page 62 The most common type of industry-standard pattern is the Pseudo-Random Binary Sequence (PRBS). PRBSs have a number of desirable properties, including the ability to simulate random data with a balanced number of 1's and 0's. Agilent J-BERT N4903B High-Performance Serial BERT...
Page 63 The closer to a continuous spectrum, the more the test signal looks like an analog noise source. The benefit of this is that such a stimulus shows any frequency- dependent effects in a device under test. For example, a clock recovery circuit Agilent J-BERT N4903B High-Performance Serial BERT...
Page 64 If your device converts the input pattern, the error detector needs a different pattern T I P than the pattern generator. See “Loading Patterns to the Pattern Generator and Error Detector” on page 73 for details. Agilent J-BERT N4903B High-Performance Serial BERT...
Page 65: User Patterns
“Pattern File Specifications” on page The Serial BERT can save files as either *.dat, *.ptrn or *.txt files. Downloading a text format pattern into your instrument may take significantly longer N O T E than a binary pattern. Agilent J-BERT N4903B High-Performance Serial BERT...
Page 66 "Data" tag. Alternating patterns require two "Data" tags. Note that the actual data starts on the line after the tag. Syntax: Data=<CR/LF><data contents> • In dual format, each character represents one bit-only the numbers '1' and '0' are allowed. Agilent J-BERT N4903B High-Performance Serial BERT...
Page 67 The Serial BERT has 32Mbits (8 MB) RAM for storing patterns. As discussed in “How the Serial BERT Generates Memory-Based Patterns” on page 69, all patterns are loaded into the RAM until a 512-bit boundary is reached. If the pattern Agilent J-BERT N4903B High-Performance Serial BERT...
Page 68 The above table is not valid for 8B/10B Comparison mode. In 8B/10B Comparison N O T E mode, the error message is generated if a pattern occupies more than 32 Mbits after reaching 512-bit boundary. Agilent J-BERT N4903B High-Performance Serial BERT...
Page 69 In this case, each half of the pattern is loaded into a separate Alternating Patterns location in the RAM. When an alternating pattern is generated, first all blocks of pattern A are sent, then all blocks of pattern B are sent, and so on. Agilent J-BERT N4903B High-Performance Serial BERT...
Page 70 For a complete list of available patterns and their description, see C:\<instrument model>\Patterns\Demo\Description.pdf For more information on the recommeded pattern for specific purposes, see “When to Use Which Pattern?” on page Agilent J-BERT N4903B High-Performance Serial BERT...
Page 71: User Patterns - Procedures
4 You can now continue with modifying the pattern according to your needs. Opening Existing Patterns To open an existing user pattern: 1 Click Edit Pattern on File menu item from the Pattern submenu. Agilent J-BERT N4903B High-Performance Serial BERT...
Page 72 5 Edit the pattern as required. For the function of the different tool buttons, see “Edit Pattern Window” on page Saving Patterns To save the current user pattern: • In the toolbar, click the Save icon. Agilent J-BERT N4903B High-Performance Serial BERT...
Page 73 Select memory slot (1 - 12). 2^n -1 PRBS Select the pattern size. 2^n PRBS Select the pattern size. Mark Density Select the pattern size and the mark density ratio. Zero Sub Select the zero substitution rate. Agilent J-BERT N4903B High-Performance Serial BERT...
Page 74 The selected patterns are immediately loaded to the pattern generator and error detector. The types of patterns that are currently loaded to the pattern generator and the error detector are always displayed in the status bar at the bottom of the screen. Agilent J-BERT N4903B High-Performance Serial BERT...
Page 75 If you allowed different patterns for the two modules: Loads the current pattern to the pattern generator. Loads the current pattern to the error detector. Captures data of specified length from the error detector. Agilent J-BERT N4903B High-Performance Serial BERT...
Page 76: User Patterns - Reference
Patterns” on page 71 details. Save Click this icon to save the current pattern. If it was not previously saved, a Save As dialog box opens for you to specify name and path for the file. Agilent J-BERT N4903B High-Performance Serial BERT...
Page 77 These functions follow Microsoft Windows Copy/ conventions. Paste/ Delete/ Undo Go To Click this icon if you want to jump to an arbitrary bit position. See “GoTo Bit Dialog Box” on page 82 for details. Agilent J-BERT N4903B High-Performance Serial BERT...
Page 78 1 bit should be present. With Overwrite mode you overwrite the bits at the cursor position. Bin/ Click this icon to open Bin/ Hex/Symbol Hex/ Configuration dialog. See Symbol “Bin/Hex/Symbol Configuration Dialog Box” on page 80 for details. Agilent J-BERT N4903B High-Performance Serial BERT...
Page 79 - Pattern A only - Patterns A and B in interleaved rows - Patterns A and B in horizontally split windows If only a standard pattern is selected, this icon has no function. Agilent J-BERT N4903B High-Performance Serial BERT...
Page 80 In this case, the Running Diparity will be applied on the full pattern (i.e. for alternate patterns, it will be applied on both A and B patterns). You can also set the Starting Running Disparity to either Automatic or Manual (+1 or -1). Agilent J-BERT N4903B High-Performance Serial BERT...
Page 81 • Editing mode (Overwrite / Dynamic Insert / Insert) • Display mode (Bin / Hex / Symbol) • Mark Density of the pattern(s) • Total Length of the pattern (in bits) • Error Indicators: Agilent J-BERT N4903B High-Performance Serial BERT...
Page 82 This text field allows you to enter a description of the pattern's characteristics or Description purpose. It can be up to 256 characters long. This text field allows you to enter the pattern length. Length in Bits Agilent J-BERT N4903B High-Performance Serial BERT...
Page 83 Standard pattern, set the Length in Bits to half the pattern length before clicking OK. Pattern Capture Dialog Box The pattern capture screen has four fields as shown in the screen below. Agilent J-BERT N4903B High-Performance Serial BERT...
Page 84 The search pattern can be entered in binary/hex/symbol format, depending on currently selected mode in pattern editor. You can continue editing the pattern while this dialog box is still open. Agilent J-BERT N4903B High-Performance Serial BERT...
Page 85 This can be used when setting up a new pattern. It can also be used as an optional technique for editing existing patterns. The Block Edit Configuration dialog box is shown in the figure below. Agilent J-BERT N4903B High-Performance Serial BERT...
Page 86 Recode and 8b/10B tab are not available. In PAM4, the 8b/10b tab is not available. 1 Fill This tab allows filling the given range in the pattern with the specified value. The available options for the Fill are: • Fill with Zeros Agilent J-BERT N4903B High-Performance Serial BERT...
Page 87 The button Convert undefined to Z provides an easy access to fix all undefined symbols to the coding of a Z symbol. It is only accessible when symbol mode is set to OOB, as there is no undefined symbol in PAM4 mode. Agilent J-BERT N4903B High-Performance Serial BERT...
Page 88 No data will be lost and what is at the start of the buffer will be at the end of the buffer after the rotation. Agilent J-BERT N4903B High-Performance Serial BERT...
Page 89 This dialog box lets you define the pattern you want to use for testing. It contains the following elements: The Error Detector Pattern in the Select Pattern dialog box allows the user patterns N O T E from file or memory user pattern. Agilent J-BERT N4903B High-Performance Serial BERT...
Page 90 Enable this checkbox if you wish to use a user-defined sequence. The patterns Sequence used in a sequence are defined in the Sequence Editor (see also “User-Defined Sequences - Concepts ” on page 96). Agilent J-BERT N4903B High-Performance Serial BERT...
Page 91: Software-Generated Prbs
(identically as for memory-based patterns), and the corresponding output is generated. See also “How the Serial BERT Generates Memory-Based Patterns” on page Range of Software-Generated PRBS Patterns The Serial BERT supports the following 2^n PRBS patterns: Agilent J-BERT N4903B High-Performance Serial BERT...
Page 92 Therefore, the mark density of such a pattern is 1/2. Some devices may have problems processing data streams with different mark density as this results in other average voltages and, thus, different electrical conditions. Agilent J-BERT N4903B High-Performance Serial BERT...
Page 93: Software-Generated Prbs - Procedures
The spectral contents of PRBS 2^n -1 patterns and the special property of decimation may also be useful in many applications (for example, for multiplexer or demultiplexer testing). Agilent J-BERT N4903B High-Performance Serial BERT...
Page 94 N O T E like the PCIe 3.0 scrambler when fed with zeroes only. The PCIe 3.0 scrambler is using D + 1 = 0, with bit numbering being reverse compared to the N4903B. Agilent J-BERT N4903B High-Performance Serial BERT...
Page 95: Hardware-Generated Prbs - Procedures
Hardware-Generated PRBS - Reference Use the Pattern Select dialog box to select the pattern(s) you want to write to the pattern generator and the error detector. See “Select Pattern Dialog Box” on page for details. Agilent J-BERT N4903B High-Performance Serial BERT...
Page 96: User-Defined Sequences
• the loops You can inspect the contents of the SequenceExpression in the Properties dialog of the Sequence Editor. The SequenceExpression uses the following keywords: Version= optional Agilent J-BERT N4903B High-Performance Serial BERT...
Page 97 Length: Must be 512 bits or a multiple thereof. Shorter or longer user patterns are automatically repeated until the next 512-bit boundary is reached (see also “How the Serial BERT Generates Memory-Based Patterns” on page 69). Agilent J-BERT N4903B High-Performance Serial BERT...
Page 98 Software-generated PRBS with polynomial 2^n cannot be referenced in a sequence. • If several PRBS patterns shall be included, all have to use the same polynomial. • Every sequence has to be downloaded to the pattern generator before it can be executed. Agilent J-BERT N4903B High-Performance Serial BERT...
Page 99: User-Defined Sequences - Procedures
A "None" block is completely ignored. – If necessary, change the block length. The block length of user patterns is derived from the file. Remember that such patterns are automatically repeated until a multiple of 512 bits is reached. Agilent J-BERT N4903B High-Performance Serial BERT...
Page 100 The sequence is shown in the Sequence Editor, but NOT automatically downloaded N O T E to the pattern generator. In contrast to loading a pattern from file, the download of a sequence requires an additional command. Agilent J-BERT N4903B High-Performance Serial BERT...
Page 101: User-Defined Sequences - Reference
For information on how to change the trigger behavior, “Sequence Trigger at Block Begin” on page 102. Number of Blocks In the Blocks field, you can directly specify the number of blocks (up to 120). Agilent J-BERT N4903B High-Performance Serial BERT...
Page 102 Divided Clock: You can use this option to generate the signal at every nth clock pulse. • Pattern: You can click Browse to launch Select User Pattern dialog. This dialog opens a browser and search for the file that contains the pattern. You can open Agilent J-BERT N4903B High-Performance Serial BERT...
Page 103 It is not possible to jump into an existing loop. It is also not possible to specify loops within loops (exept the default overall loop). For information on how to create a loop, see “Creating a New Sequence” on page Agilent J-BERT N4903B High-Performance Serial BERT...
Page 104 Sequence execution continues with the next block. The pattern generator reacts on the end condition as soon as the pattern has N O T E finished. Sequence Editor Toolbox The Sequence Editor toolbox provides the following functions: Agilent J-BERT N4903B High-Performance Serial BERT...
Page 105 This icon appears green if the sequence has not been sent to the PG. For instance, if the sequence had been loaded from file or been changed since last sent to PG. Agilent J-BERT N4903B High-Performance Serial BERT...
Page 106 If the sequence start condition is a signal at the Aux In port, the sequence restarts upon the specified signal. If the sequence start condition is "Command", sequence execution starts when the Start button is clicked. Agilent J-BERT N4903B High-Performance Serial BERT...
Page 107 A window that shows the present SequenceExpression (for details see “How a Sequence Expression Sequence is Defined” on page 96). You can edit the SequenceExpression in this field. Any changes override the previous settings. Agilent J-BERT N4903B High-Performance Serial BERT...
Page 108: Sequencer-Pattern Editor
You can do the following tasks in the sequencer-pattern editor window: Creating New Patterns in Sequencer-Pattern Editor To create a new pattern (standard or alternate): 1 Click Sequence Editor menu item from the Pattern submenu. Agilent J-BERT N4903B High-Performance Serial BERT...
Page 109 4 Click Edit Pattern(s) to launch Pattern Editor for second channel. 5 Use the standard keyboard functions to edit patterns at the position of the cursor. 6 In the toolbar, click Apply to confirm the new changes. Agilent J-BERT N4903B High-Performance Serial BERT...
Page 110: Sequencer-Pattern Editor - Reference
Export Trace Click this icon to open Export Trace dialog. See “Export Trace” on page for details. Agilent J-BERT N4903B High-Performance Serial BERT...
Page 111 Cut/ These functions follow Microsoft Windows Copy/ conventions. Paste/ Delete/ Undo Properties Click this icon to view/ change the properties of the current pattern(s). See “Pattern Properties” on page 119 for details. Agilent J-BERT N4903B High-Performance Serial BERT...
Page 112 Click this icon to edit a block of data in the pattern (s). See “ Block Edit Configuration Dialog Box” on page 85 for details. Select Click this icon to select all the bits in the pattern. Agilent J-BERT N4903B High-Performance Serial BERT...
Page 113 See “GoTo Bit Dialog Box” on page 82 details. Bin/ Click this icon to open Bin/ Hex/Symbol Hex/ Configuration dialog. See Symbol “Bin/Hex/Symbol Configuration Dialog Box” on page 80 for details. Agilent J-BERT N4903B High-Performance Serial BERT...
Page 114 Out and/or Aux Data Out Channel and offers you to edit it. Access to this editor is only possible from within the sequence editor. The pattern editor canvas for sequencer-pattern editor is shown in the figure below. Agilent J-BERT N4903B High-Performance Serial BERT...
Page 115 The available functions to change the view and to modify the pattern are described “Edit Pattern Window for Sequencer-Pattern Editor” on page 110. Create New Pattern The Create New Pattern dialog is shown in the figure below. Agilent J-BERT N4903B High-Performance Serial BERT...
Page 116 The Symbol Settings dialog is used to select the symbol mode. It displays the calculated output levels based on the current Data Out and Aux Data Out levels. The Symbol Settings dialog is shown in the figure below. Agilent J-BERT N4903B High-Performance Serial BERT...
Page 117 The PAM4 Mode is only valid in 'Bin' representation. The 'Hex' and 'Symbol' N O T E representations are disabled in this mode. You need to press the described keys to configure 'Z' in the hardware front panel N O T E for OOB Mode. Agilent J-BERT N4903B High-Performance Serial BERT...
Page 118 Export either Data Out or Aux Data Out as Standard pattern, or both as an Alternate pattern. • Description: Add a description for the captured Pattern. • File name: Provide a name to the file. • Export: Click this button to export the file at the given location. Agilent J-BERT N4903B High-Performance Serial BERT...
Page 119 It can be up to 256 characters long. • Pattern Type: Pattern type of pattern. This field is non-editable. • Length in Bits: Pattern length in bits. This field is editable. Agilent J-BERT N4903B High-Performance Serial BERT...
Page 120 Setting up Patterns Agilent J-BERT N4903B High-Performance Serial BERT...
Page 121: Setting Up The Pattern Generator
Agilent J-BERT N4903B High-Performance Serial BERT User Guide Setting up the Pattern Generator Setting up the Pattern Generator - Concepts The Serial BERT's pattern generator generates an output signal based on a data pattern. It has the following possibilities for generating an output signal: •...
Page 122: Input And Output Ports
Allows you to connect a device that generates a trigger for inserting a single bit error in the output stream. In addition, it also allows you to control the electrical idle state of Data Out and/or Aux Data Out. Agilent J-BERT N4903B High-Performance Serial BERT...
Page 123 The pattern generator's Data Out, Clock Out, Aux Data Out, Trigger/Ref Clock Out N O T E and Aux Clk Out ports must be terminated with 50 Ω if they are not connected. Agilent J-BERT N4903B High-Performance Serial BERT...
Page 124 The GUI shows an error message, listing the effected outputs and highlights the Outputs On status indicator: In the corresponding Output screen of the PG Setup, the output settings that currently don’t match the electrical output settings are highlighted in yellow. Agilent J-BERT N4903B High-Performance Serial BERT...
Page 125 In the M8061A window, the parameters that currently do not match the data out settings are highlighted in yellow. The parameters can be changed to configure the output according to the DUT’s termination requirements. The changes are applied only when the output protection circuit button is clicked. Agilent J-BERT N4903B High-Performance Serial BERT...
Page 126 The changes are applied only when the output protection circuit button is clicked. Understanding the Output Level Parameters The following figure shows the parameters of a Data, Aux Data, Clock, or Trigger/ Ref Clock output signal. Agilent J-BERT N4903B High-Performance Serial BERT...
Page 127 This varies the phase relationship of the data and clock outputs (causes the data pulse to have a certain time delay after the clock pulse). The higher the delay, the greater the time difference between the clock signal and the data signal. Agilent J-BERT N4903B High-Performance Serial BERT...
Page 128 No, the warning message closes with no changes to the terminations. If you answer Yes, the data termination voltage is applied and the Logic Level is changed to CUSTOM. See also “Why Incorrect Terminations Could Damage Your Device” on page 129. Agilent J-BERT N4903B High-Performance Serial BERT...
Page 129 Choosing wrong terminations may cause your device to output voltage levels that are not as expected. It may also cause excessive current or current flow in the wrong direction, which can damage your device. Agilent J-BERT N4903B High-Performance Serial BERT...
Page 130 You must ensure, however, that the network is oriented correctly. If it is not, damage may occur to your device or instrument. The diagram below shows a bias tee that is positioned correctly. Notice that the pattern generator's outputs are protected by the blocking capacitor. Agilent J-BERT N4903B High-Performance Serial BERT...
Page 131: Input And Output Ports - Procedures
Output ports of the pattern generator that are not connected to another device must be terminated with 50 Ohm to prevent the Serial BERT from damage. Note that for unconnected ports, an internal protection circuit automatically reduces the output voltages to safe levels. Agilent J-BERT N4903B High-Performance Serial BERT...
Page 132 After the De-Emphasis function has been enabled using the External Instrument (s) - Config menu, the following parameters are visible in PG Data Output screen. Controlling the N4916A De-Emphasis Signal Converter For N4916A, you have de-emphasis amplitude (post–cursor) and the corresponding unit. Agilent J-BERT N4903B High-Performance Serial BERT...
Page 133 You can toggle between dB and percent. Toggling does not change the value. When N4916A/B De-Emphasis Signal Converter is connected then the X offset and N O T E Output Blanking will not be visible in the PG-Data Output window. Agilent J-BERT N4903B High-Performance Serial BERT...
Page 134 The following topics tell you how to use the pattern generator's input ports: • “Bit Rate - Procedures” on page 141 • “Delay Control Input - Procedures” on page 156 • “Manually Inserting Errors” on page 157 • “Setting Up a Periodical Output” on page 162 Agilent J-BERT N4903B High-Performance Serial BERT...
Page 135: Input And Output Ports - Reference
Data Offset and Clock Offset knob T I P on the front panel. “Understanding the Output Level Parameters” on page 126 for information about how the Serial BERT modifies the output levels. Agilent J-BERT N4903B High-Performance Serial BERT...
Page 136 Enter the desired value directly with the numeric keyboard. • Use the knob by the numeric keyboard to fine-tune the value. You can also adjust delay with the Data Out Delay knob on the front panel. T I P Agilent J-BERT N4903B High-Performance Serial BERT...
Page 137 Logic Level, the terminations are set accordingly. It is recommended that you keep the default values of the terminations. “Understanding how the Serial BERT Uses Logic Families and Terminations” on page 128 for additional information. Agilent J-BERT N4903B High-Performance Serial BERT...
Page 138 Idle is controlled via the existing Error Add Input, which will loose its error insertion functionality when used for Electrical Idle. The "Electrical Idle" checkbox is invisible when the N4876A Multiplexer is N O T E connected to the N4903B Serial BERT. Agilent J-BERT N4903B High-Performance Serial BERT...
Page 139: Bit Rate
When to Use an External Clock Source? The Serial BERT's internal clock can be used for most testing purposes. There are some circumstances, however, when an external clock source is required: • Synchronization with an external clock Agilent J-BERT N4903B High-Performance Serial BERT...
Page 140 If the bit rate exceeds 620 Mbit/s, the limitations no longer apply. The following figure clarifies the behavior in the range between 615 Mbit/s and 620 Mbit/s: Limitations do not apply in this range Bitrate [Mbit/s] Limitations apply in this range Agilent J-BERT N4903B High-Performance Serial BERT...
Page 141: Bit Rate - Procedures
For more information on SSC, see “Jitter Setup - Concepts ” on page 404. Bit Rate - Procedures You can use an external clock source or the Serial BERT's internal clock to control the bit rate. Agilent J-BERT N4903B High-Performance Serial BERT...
Page 142 The selected clock rate applies to the pattern generator. This is also the clock rate generated at the pattern generator's Clock Out port. If the error detector receives its clock from the pattern generator, it runs at the same clock rate. Agilent J-BERT N4903B High-Performance Serial BERT...
Page 143: Bit Rate - Reference
The internal clock (i.e. the bitrate) is the external clock divided by the value specified in the clock divider field. The external clock divider field is available if you have closen an external clock source. Agilent J-BERT N4903B High-Performance Serial BERT...
Page 144 Delete Preset Button Select a preset clock rate in the Preset list and click this button to remove it from the list. You can only delete presets that are user-defined. Agilent J-BERT N4903B High-Performance Serial BERT...
Page 145: Trigger/Ref Clock Output
Trigger/Ref Clock Output - Procedures To set up the pattern generator's Trigger/Ref Clock Output port: 1 Connect the external instrument to the Trigger/Ref Clock Out port. 2 Click Trigger/Ref Clock Setup menu item from the PG Setup submenu. Agilent J-BERT N4903B High-Performance Serial BERT...
Page 146: Trigger/Ref Clock Output - Reference
If the Divider Factor n is uneven (For example 3), the clock's duty cycle will not be N O T E 50%, but the signal will stay high for (n+1)/2 and low for (n-1)/2. This results in a Duty Cycle Distortion (DCD) of 0.5 UI. Agilent J-BERT N4903B High-Performance Serial BERT...
Page 147 In Sequence mode, the Trigger/Ref Clock Out can generate a spike whenever the execution of a block starts or restarts. Whether that happens for a particular block or not is defined for each block individually in the SequenceExpression. See also “Sequence Block Parameters” on page 102. Agilent J-BERT N4903B High-Performance Serial BERT...
Page 148 A trigger pulse is sent when this pattern is found in the PRBS. The trigger repetition rate is one pulse per 512 pattern repetitions. Example: Pattern length: 2^7-1 (127) bits N-bit pattern: 1110001 Agilent J-BERT N4903B High-Performance Serial BERT...
Page 149: Aux Data Out
Click Aux Data Setup in the PG Setup menu. A PG Aux Data Output dialog opens as shown in the figure below. • Select the mode for the Aux Data Output. You can select from the following options: Agilent J-BERT N4903B High-Performance Serial BERT...
Page 150 From the PG Setup menu, click Aux Data Setup to open PG Aux Data Output dialog. • Select "Second Channel". • Create your pattern for the Aux Channel in the Pattern Editor by opening the “Edit Pattern on File” even if you don’t have a pattern on file. Agilent J-BERT N4903B High-Performance Serial BERT...
Page 151 1 Click "Properties" icon to set up the properties of the current pattern, including parameters and length. 2 Use the pattern editor canvas to set up your pattern. 3 Click "Save" icon to save your pattern. Agilent J-BERT N4903B High-Performance Serial BERT...
Page 152 Setting up the Pattern Generator • From the Pattern menu, click Sequence Editor. • You will be now able to select edit and drop in the data you want on both the Regular Channel and the Aux Channel. Agilent J-BERT N4903B High-Performance Serial BERT...
Page 153 Setting up the Pattern Generator • Send the patterns to the outputs by pressing “To PG”. You should be now able to send the data. Agilent J-BERT N4903B High-Performance Serial BERT...
Page 154: Aux Data Output - Reference
“N4876A System Setup Adjustment” on page 490. In multiplexer mode, the pattern for the PG is automatically split between Data Out and Aux Data Out. This mode is intended to stimulate multiplexing devices without Agilent J-BERT N4903B High-Performance Serial BERT...
Page 155: Delay Control Input
“Jitter Tolerance Tests - Concepts ” on page 395. The delay control input is equipped with overvoltage protection. If the applied voltage is too high, the input is automatically disabled, and the following dialog appears: Agilent J-BERT N4903B High-Performance Serial BERT...
Page 156: Delay Control Input - Procedures
Delay Control Input - Reference This checkbox in the PG Data Setup window is used to disable or enable the Delay Control In port, where you can supply an external signal to add jitter to the output signal. Agilent J-BERT N4903B High-Performance Serial BERT...
Page 157: Error Addition/Insertion
Error Add Setup menu item from the PG Setup submenu to open the Error Add Setup dialog box. 3 Select Off and click OK to close the dialog box. Agilent J-BERT N4903B High-Performance Serial BERT...
Page 158 – Average Number of Bits Between Errors allows you to specify the average number of regular (correct) bits that are sent without errors before inserting the next error. 4 Click OK to close the dialog box. Agilent J-BERT N4903B High-Performance Serial BERT...
Page 159: Error Addition/Insertion - Reference
The Error Add button in the top right corner is used to insert a single bit error in the data stream. This button is always active, even if other error insertion mechanisms are running. The maximum number of errors that this function supports is one error per 128-bit block. Agilent J-BERT N4903B High-Performance Serial BERT...
Page 160 With this option selected, when a rising edge is detected at the Error Add port, an error will be generated in the output stream by flipping a single bit within a bit block of 128 bits. The signals received at this port must be TTL-compatible. Agilent J-BERT N4903B High-Performance Serial BERT...
Page 161: Pattern Alternation
A and one for pattern B. The differences between these patterns are: • Standard patterns consist of one single pattern that is repeatedly sent. Any arbitrary pattern up to 32Mbit length can be set up. However, there are no Agilent J-BERT N4903B High-Performance Serial BERT...
Page 162: Pattern Alternation - Procedures
To configure the pattern generator to generate periodical data output: 1 Click Alt. Pattern and Aux In menu item from the PG Setup submenu to open the Alternate Pattern Control dialog box. 2 Select one of the following options: Agilent J-BERT N4903B High-Performance Serial BERT...
Page 163 The signals received at this port must be TTL-compatible. The granularity for the insertion of pattern B via external signal is 512 bits. 2 Click Alt. Pattern and Aux In menu item from the PG Setup submenu to open the Alternate Pattern Control dialog box. Agilent J-BERT N4903B High-Performance Serial BERT...
Page 164: Pattern Alternation - Reference
These functions are only available if Alternate Pattern is selected in the Pattern N O T E Properties dialog box. Continuous A Select this option to send out only pattern A repeatedly. Data Out A A A A A A A A A A A A Agilent J-BERT N4903B High-Performance Serial BERT...
Page 165 With this option selected, the signal at the Aux In port will be ignored. • Level Sensitive – If Aux In is logic high, pattern B is sent. – If Aux In is logic low, pattern A is sent. Agilent J-BERT N4903B High-Performance Serial BERT...
Page 166 Due to the pattern generator behavior, the patterns may be repeated up to 512 times N O T E before alternating. See “How the Serial BERT Generates Memory-Based Patterns” on page 69 for details. Agilent J-BERT N4903B High-Performance Serial BERT...
Page 167: Setting Up The Error Detector
Agilent J-BERT N4903B High-Performance Serial BERT User Guide Setting up the Error Detector Setting up the Error Detector - Concepts The error detector analyzes an incoming bit stream, compares it to the expected pattern, and locates any inconsistencies. The error detector requires the following settings to work correctly: •...
Page 168: Inputs And Outputs
Inputs and Outputs Inputs and Outputs - Concepts The error detector (ED) provides input and output ports for running tests and for connecting external equipment. The error detector has the following inputs and outputs: Agilent J-BERT N4903B High-Performance Serial BERT...
Page 169 Use this port to send a trigger signal to another connected device, such as an oscilloscope. • Error Out This signal can be used to trigger an external instrument to help in error analysis. When any number of errors are located within a 128-bit data block, a Agilent J-BERT N4903B High-Performance Serial BERT...
Page 170 Data In connections. You can specify the termination by entering the termination voltage in the respective field. Selecting the wrong termination may damage your device. C A U T I O N Agilent J-BERT N4903B High-Performance Serial BERT...
Page 171: Inputs And Outputs - Procedures
Selecting the wrong termination may damage your device. C A U T I O N 4 Select the Data Inverted checkbox if your device inverts data. You can now physically connect the DUT to the error detector. Agilent J-BERT N4903B High-Performance Serial BERT...
Page 172: Data Input Setup - Reference
(for example, any application using bursts), because the averaged 0/1 threshold voltage will drift from the correct level when there is no input. The manually set threshold voltage must of course be within the input range. Agilent J-BERT N4903B High-Performance Serial BERT...
Page 173: Clock Setup
To measure the Bit Error Rate with the error detector, the bit rate of the data stream must be known. Depending on the options the instrument is delivered with, you could use either an external clock source for the error detector (for example, the Agilent J-BERT N4903B High-Performance Serial BERT...
Page 174 Above the bandwidth the loop cannot track such a modulation completely, and thus, the response to the modulation is attenuated. The other loop parameter is peaking. This describes how much a modulation is exaggerated (mostly close to the loop bandwidth). Agilent J-BERT N4903B High-Performance Serial BERT...
Page 175 For this reason, the clock recovery circuitry has it's own comparator for the incoming data. This comparator also needs to know the threshold voltage (0/1 decision threshold). Agilent J-BERT N4903B High-Performance Serial BERT...
Page 176 The limitations apply to the instrument according to the following hysteresis curve: • If the bit rate falls below 615 Mbit/s, the limitations apply. • If the bit rate exceeds 620 Mbit/s, the limitations no longer apply. Agilent J-BERT N4903B High-Performance Serial BERT...
Page 177 Clock Falling Edge checkbox on the Sampling Point Setup screen of the error detector setup. 2 ns Clock 500 Mbit/s Sampling Point Delay Rising Edge Sampling Point Delay Falling Edge Covered Range Agilent J-BERT N4903B High-Performance Serial BERT...
Page 178: Clock Setup - Procedures
CDR Fine Adjust and Peaking values. When using a Preset, this is only required when you want to change these values. 7 Enable Spread Spectrum; and adjust the deviation (%) and deviation type as required. Agilent J-BERT N4903B High-Performance Serial BERT...
Page 179: Clock Setup - Reference
Use the numeric keypad to enter the value followed by the unit that you can select with the G/n, M/μ, k/m, and X1 keys on the front panel. Alternatively, you can select a value from the Preset list. Agilent J-BERT N4903B High-Performance Serial BERT...
Page 180 (%). Click 'measure' to measure and update the transition density. This parameter affects the loop bandwidth, and thus must be either entered correctly or measured. Some standards specify the loop bandwidth for a given Agilent J-BERT N4903B High-Performance Serial BERT...
Page 181 For measurements with partly invalid data, such as burst tests, this function may cause a clock loss. In such cases, deactivate Auto Threshold and • enter a fixed voltage level manually, or Agilent J-BERT N4903B High-Performance Serial BERT...
Page 182: Error Ratio
Ratio (ISR), Disparity Error Ratio (DER) along with the calculated BER (cBER). You need to set the error ratio mode from Comparison the J-BERT's Error Detector - Error Ratio window. For more information, see “Setting up Error Ratio” on page 185. Agilent J-BERT N4903B High-Performance Serial BERT...
Page 183 ED has to recognize the 10B Data and filler symbols (of both disparities) and to ignore the insertion or deletion of filler symbols. The following figure shows the functional block diagram of Option A02. Agilent J-BERT N4903B High-Performance Serial BERT...
Page 184 For recognition of these special symbols one bit error correction is performed on header, SKP and SKP_END symbol each. The "Bit Comparison without USB3.1 SKPOS" option is only applicable for USB 3.1 testing. Agilent J-BERT N4903B High-Performance Serial BERT...
Page 185: Error Ratio - Procedures
Recovery (CDR) from the Clock Setup window. For more information, see “Clock Setup - Procedures” on page 178. 3 From the main menu, choose ED Setup and then click Error Ratio from the list of menu items. This will launch Error Ratio window. Agilent J-BERT N4903B High-Performance Serial BERT...
Page 186 If you select error ratio based on "Bit Comparison", "Bit Comparison without PCIe3 SKPOS" or "Bit Comparison without USB3.1 SKPOS", skip steps 5 to 11 and go to step 12. Agilent J-BERT N4903B High-Performance Serial BERT...
Page 187 8 Select a preset in the Setup list and click Delete Preset button to remove it from the list. You can only delete presets which are defined by the user. Agilent J-BERT N4903B High-Performance Serial BERT...
Page 188 Select "Manual" mode to disable the automatic alignment and initiate re- alignment if alignment is not already done or lost. • Click ReAlign button to re-align the symbols again, in case, if the symbol alignment is lost. Agilent J-BERT N4903B High-Performance Serial BERT...
Page 189 Results window. For more information, refer “BER Results Window” on page 366. The "Bit Comparison without USB3.1 SKPOS" results can be viewed in the BER Results window. For more information, refer “BER Results Window” on page 366. Agilent J-BERT N4903B High-Performance Serial BERT...
Page 190: Error Ratio - Reference
Each filler primitive can consist of upto 4 filler symbols. Filler symbols are separated by a comma (,). Example: For SAS we have 4 filler primitives each consisting of 4 filler symbols. K28.5,D10.2,D10.2,D27.3 K28.5,D7.0,D7.0,D7.0 K28.5,D1.3,D1.3,D1.3 K28.5,D27.3,D27.3,D27.3 The following are the supported standards along with their filler symbols: Agilent J-BERT N4903B High-Performance Serial BERT...
Page 191 In this case, all allowed D and K symbols will match and are removed from incomming DUT data. For example: K28.1, * Here the asterisk (*) symbol will be treated as don't care. Agilent J-BERT N4903B High-Performance Serial BERT...
Page 192 8b10b Error indicator. Invalid Symbols in ED are shown as N/A in pattern editor. Running disparity errors in ED data mark the corresponding symbol with red color in the pattern editor. Agilent J-BERT N4903B High-Performance Serial BERT...
Page 193: Sampling Point Setup
It is typically produced by triggering the oscilloscope with a synchronous clock signal. When the oscilloscope is triggered by a clock signal, data patterns will not be examined. Instead, if persistence is set high enough, the shape of an "eye" will be Agilent J-BERT N4903B High-Performance Serial BERT...
Page 194 • The instantaneous bit error ratio (BER) is greater than or equal to the alignment BER threshold. • An adjacent point has an instantaneous BER that is less than the alignment BER threshold. Agilent J-BERT N4903B High-Performance Serial BERT...
Page 195 In bit recovery mode, some restrictions apply: • Synchronization is impossible, because no particular data is expected. Sync now and auto synchronization functions are disabled. • Burst mode is disabled. Agilent J-BERT N4903B High-Performance Serial BERT...
Page 196: Sampling Point Setup - Procedures
You may click Cancel at any time. 4 Now you can use the numeric keypad or front panel knob to manually adjust the value in the Data Delay field. Agilent J-BERT N4903B High-Performance Serial BERT...
Page 197 The bit recovery mode (BRM) allows you to measure the relative BER without knowing the incoming data pattern. To enable the bit recovery mode: 1 Click Sampling Point Setup menu item from the ED Setup submenu. Agilent J-BERT N4903B High-Performance Serial BERT...
Page 198: Sampling Point Setup - Reference
Click anywhere in the sampling point display. The sampling point will be moved to that location. • Turn the Decision Threshold knob on the front panel. A small window appears, displaying the threshold value. This knob can be used at any time, while in any window. Agilent J-BERT N4903B High-Performance Serial BERT...
Page 199 In SER mode, the Auto Align with CDR enabled supports the ED frequency above N O T E 11.5 Gb/s and performs Data Centre with appropriate threshold settings. Alternatively, you can also press the Auto Align button on the front panel. T I P Agilent J-BERT N4903B High-Performance Serial BERT...
Page 200 This tip does not apply in cases of severe pattern dependent jitter or with devices that do not work with PRBS patterns. This function uses the alignment BER threshold to determine the left and right eye N O T E edges. Agilent J-BERT N4903B High-Performance Serial BERT...
Page 201 Activate this checkbox to make the error detector continuously set the 0/1 threshold level to the average DC voltage level of the incoming data signal. Manual 0/1 threshold changes are impossible while this function is selected. N O T E Agilent J-BERT N4903B High-Performance Serial BERT...
Page 202 Click this button to return the 0/1 Threshold and Data Delay to the values measured during the last auto alignment. The Data Inverted and Avg. 0/1 Threshold checkboxes will be returned to their previous state. Agilent J-BERT N4903B High-Performance Serial BERT...
Page 203: Trigger And Aux Output
If Data is selected, the input data is output over a comparator at Aux Out. The comparator is controlled by the 0/1 threshold. This lets you use an oscilloscope to determine if the 0/1 threshold is correctly set. If the 0/1 Agilent J-BERT N4903B High-Performance Serial BERT...
Page 204: Trigger And Aux Output - Reference
Hence next trigger will be processed only after this period. The Filler Detected option will be available only if you have selected the error ratio N O T E based on 8B/10B symbol comparison. • SKPOS Detected Agilent J-BERT N4903B High-Performance Serial BERT...
Page 205: Pattern Synchronization
The Serial BERT calculates bit error rates by comparing the received data with the expected data patterns. To do this, it needs to know where the start of the pattern is located in the data stream. Agilent J-BERT N4903B High-Performance Serial BERT...
Page 206 Single instance of the detect word in the data stream Expected Incoming Pattern Bit stream Reference Detect Word Point 48 bits Detect Word Correct Sync 48 bits Detect Word 48 bits • Multiple instances of the detect word with correct synchronization Agilent J-BERT N4903B High-Performance Serial BERT...
Page 207 Detect Word 48 bits If the error detector attempts to synchronize on the incorrect detect word, the BER will be unacceptably high, and, if automatic synchronization is selected, the error detector attempts another resync. Agilent J-BERT N4903B High-Performance Serial BERT...
Page 208 This mode doesn't allow the analyzer to automatically synchronize if the BER becomes greater than the sync threshold. For example, the analyzer will not re- synchronize after momentary clock loss. Agilent J-BERT N4903B High-Performance Serial BERT...
Page 209 (reference alignment 2 and 3). For exact alignment, the sync threshold must be set lower than the BER caused by a 1 bit misalignment, in this case 1E-3. Agilent J-BERT N4903B High-Performance Serial BERT...
Page 210 BER threshold. If you are using these functions and want to consistently re-synchronize at a lower sync threshold, you must set the alignment BER threshold to the same value as the sync threshold BER. Agilent J-BERT N4903B High-Performance Serial BERT...
Page 211 The burst sync mode is disabled in "8B/10B Comparison", "Bit Comparison without N O T E PCIe3 SKPOS" and "Bit Comparison without USB3.1 SKPOS" error ratio modes. Agilent J-BERT N4903B High-Performance Serial BERT...
Page 212 See “How does Clock Data Recovery Work?” on page 174 for more information. If an external clock is used, there is no delay. The clock signal must however be continuous. Agilent J-BERT N4903B High-Performance Serial BERT...
Page 213 CDR Settling Time Synchronization Time Data Input Burst Begin Margin End Margin Bit Count Time Gate Input Gate Gate Active Passive Gate Active is the interval in which the Gate In signal is active. Agilent J-BERT N4903B High-Performance Serial BERT...
Page 214 Valid after Gate CDR mode: 1.5 microseconds Non-CDR mode: 1536 bits Gate Passive CDR mode: 2560 bits or 1.5 microseconds (whichever is larger) Non-CDR mode: 2560 bits The following values can be derived from these parameters: Agilent J-BERT N4903B High-Performance Serial BERT...
Page 215 (thus increasing the bad burst count). You can typically reduce the bad burst count by starting the gating period later. CDR Settling Time Start too soon Synchronization Time Burst Data Input Gate Input Settling/Synchronization fail here Attempted Settling Time ends here Agilent J-BERT N4903B High-Performance Serial BERT...
Page 216: Pattern Synchronization - Procedures
End too late Synchronization Time Burst Data Input Bit Count Time Gate Input Pattern Synchronization - Procedures To synchronize the incoming pattern to the expected pattern: 1 Press Pattern Sync in the ED Setup menu. Agilent J-BERT N4903B High-Performance Serial BERT...
Page 217 By default, counting with one error is selected. Unselecting the Mask Resync Errors option disables the Mask Resync Errors feature. By default, the Mask Resync Errors feature is enabled. N O T E Agilent J-BERT N4903B High-Performance Serial BERT...
Page 218: Pattern Synchronization - Reference
All cases of dropped or additional bits causes the error detector to lose synchronization. If the error detector loses synchronization it keeps counting bit, symbol, frame errors and generally the measurement won’t reflect the DUT’s performance Agilent J-BERT N4903B High-Performance Serial BERT...
Page 219 Other counters such as disparity error, illegal symbol counter and filler symbol counter are discarded for 200ms during re-synchronization of the error detector. Agilent J-BERT N4903B High-Performance Serial BERT...
Page 220: Error Accumulation
Use the Browse button to select a different directory. 6 Click OK to apply your selections and close the Accumulation Setup dialog box. For more information on how to run error accumulation tests, see “How to Run Accumulated Measurements” on page 377 Agilent J-BERT N4903B High-Performance Serial BERT...
Page 221: Error Accumulation - Reference
However, in Repeat mode, the results of all repetitions will be appended to this file and no information is lost. • No Logging Click this option to turn off measurement logging. Serial BERT will not save the test results. Agilent J-BERT N4903B High-Performance Serial BERT...
Page 222 Click this button to browse for the directory where you wish to save the measurement log files. Changes to the parameters of the accumulation setup do not take effect until the N O T E start of the next accumulation. Agilent J-BERT N4903B High-Performance Serial BERT...
Page 223: Ber Location
The Bit Error Location Mode dialog box offers the following options: The Single Bit option is disabled in "8B/10B Comparison", "Bit Comparison without N O T E PCIe3 SKPOS" and "Bit Comparison without USB3.1 SKPOS" error ratio modes. Agilent J-BERT N4903B High-Performance Serial BERT...
Page 224: Audio Signals
The use of warning tones is convenient when you want to monitor the instantaneous BER over a longer time without constantly watching the display. With the Audio dialog box, you can adjust the sound volume as well as some conditions when to play a sound. Agilent J-BERT N4903B High-Performance Serial BERT...
Page 225: Audio Signals - Procedures
Select this checkbox to enable the audio function. Clear this checkbox if you want to switch off the audio function. You can also use the Audio On/Off button on the front panel to accomplish the same function. Agilent J-BERT N4903B High-Performance Serial BERT...
Page 226 Tones on All Error Rates Click this option to make the analyzer produce warning tones when any BER greater than zero is measured. The pitch will increase or decrease as the BER increases or decreases. Agilent J-BERT N4903B High-Performance Serial BERT...
Page 227: Advanced Analysis
Agilent J-BERT N4903B High-Performance Serial BERT User Guide Advanced Analysis Advanced Analysis - Concepts The Serial BERT offers several different kinds of advanced measurements for various purposes: DUT Output Timing/Jitter This type of measurement is used to measure the timing and jitter behavior for a device under test (DUT).
Page 228 For examples, refer to the descriptions of the different measurements. Optimizing Parameters If the presented measurement results do not answer your questions adequately, you can easily modify the setup parameters in the Properties dialog box. When Agilent J-BERT N4903B High-Performance Serial BERT...
Page 229: Advanced Analysis - Procedures
To save a measurement as an .mcp file for later use in the Serial BERT user interface: 1 After your measurement has finished and the results are displayed, select Save Measurement from the Analysis menu. 2 Select a proper file name and location and press the Save button. Agilent J-BERT N4903B High-Performance Serial BERT...
Page 230 3 Open the Edit menu (or context menu) once more and select Paste. This inserts a copy of the chosen measurement results. For an Output Levels measurement, this looks as shown below: Agilent J-BERT N4903B High-Performance Serial BERT...
Page 231 1 Select Load Measurement from the Analysis menu. 2 Use the file dialog box to locate the desired .mcp file and press Open to load the measurement. The respective screen of the Analysis panel opens and you can view the measurement. Agilent J-BERT N4903B High-Performance Serial BERT...
Page 232 How to Change the Colors of the Graph You can customize the colors of the graphical display. This function is common to all measurements: 1 In the Properties dialog box, switch to the Colors tab. Agilent J-BERT N4903B High-Performance Serial BERT...
Page 233 3 Use the Color Set and the Color Palette to select the new color. 4 To view the results of your changes, press Apply. This immediately updates the measurement window, where you can see the new colors. 5 Press OK to close the Properties dialog box. Agilent J-BERT N4903B High-Performance Serial BERT...
Page 234: Advanced Analysis - Reference
Delay:;Relative [1:1] SerialBERT;;; Delay;Threshold;BER(All); -3.878757E-011;1.504954E-001;2.497699E-001; 3.878757E-011;1.504954E-001;2.499503E-001; -1.551503E-011;3.504954E-001;4.922570E-001; 1.551503E-011;3.504954E-001;4.952636E-001; -1.551503E-011;-4.950459E-002;0.000000E+000; 1.551503E-011;-4.950459E-002;0.000000E+000; This file can be imported into spreadsheet applications such as Microsoft Excel, for example. Use the semicolons as delimiters for the rows or columns. Agilent J-BERT N4903B High-Performance Serial BERT...
Page 235 One unit interval is the equivalent of one clock period. To convert a time value to a unit interval value, divide it by the pulse period or multiply it by the clock frequency. Agilent J-BERT N4903B High-Performance Serial BERT...
Page 236 DUT Output Timing/Jitter measurement, the software provides two types of markers. Linear Markers The following illustration shows the definitions for the markers and the values that can be derived from the marker position. Agilent J-BERT N4903B High-Performance Serial BERT...
Page 237 DUT Output Timing/Jitter measurement • Output Levels measurement The Gaussian marker allows to measure the normal distribution of measurement results. The distribution of random values is called normal, if it can be described by the following formula: Agilent J-BERT N4903B High-Performance Serial BERT...
Page 238 The marker has three handles that can be dragged: two for adjusting its width, one for changing its height and position. The following figure shows an exemplary DUT Output Timing/Jitter measurement result with a Gaussian marker. The marker readout provides the following information: Agilent J-BERT N4903B High-Performance Serial BERT...
Page 239 You can thus determine how parts of the jitter histogram contribute to the overall jitter values. You may have measured a bathtub curve like the one shown below: Agilent J-BERT N4903B High-Performance Serial BERT...
Page 240 (see “dBER vs. Threshold Graph” on page 274). In the example below, μ (Mu) and σ (Sigma) will be the same as the Level and Standard Deviation results calculated by the measurement. Agilent J-BERT N4903B High-Performance Serial BERT...
Page 241: Dut Output Timing/Jitter
DUT with maximum confidence. DUT Output Timing/Jitter includes the Fast Total Jitter measurement that can be used to measure the total jitter for devices which generate a very low error density in a reasonable time span. Agilent J-BERT N4903B High-Performance Serial BERT...
Page 242 Fast Total Jitter measurement can, for example, determine the total jitter at a BER of 10 in less than 20 minutes (at a data rate of 10 Gbit/s). For details refer to “Explanation of the Fast Total Jitter Measurement” on page 246. Agilent J-BERT N4903B High-Performance Serial BERT...
Page 243 After the output timing behavior of the DUT is measured, the Serial BERT calculates the different jitter components: Random and Deterministic Jitter To understand the RJ and DJ results, it is helpful to first understand how the software generates the results: 1 The bathtub curve is measured. Agilent J-BERT N4903B High-Performance Serial BERT...
Page 244 The estimated TJ is the period minus the width of the eye opening. The illustration below shows a jitter curve where both RJ and DJ are present. It also shows how the TJ peak-to-peak and RMS are calculated. Agilent J-BERT N4903B High-Performance Serial BERT...
Page 245 Residual BER for RJ/DJ Separation level. The estimated TJ is the period minus the width of the measured eye. The following graphic is not available from the measurement software. It is inserted N O T E here to show how the TJ period is calculated. Agilent J-BERT N4903B High-Performance Serial BERT...
Page 246 Quite often, we do not need to measure the exact BER, but can stop the measurement if we are sure that the BER is above or below a threshold. In a jitter tolerance test, for example, we need just to assure that the device under test Agilent J-BERT N4903B High-Performance Serial BERT...
Page 247 The BER threshold of 10 and hence the setting of the multiplication factor to is just an example-by changing the exponent, the table applies analog to other thresholds. The following figure shows a plot of this table. Agilent J-BERT N4903B High-Performance Serial BERT...
Page 248 Since we are unable to find a single point on the slope where the BER is exactly , we search for an interval that brackets the point at which the BER is equal to 10 . This is illustrated for the left-hand slope in the following figure. Agilent J-BERT N4903B High-Performance Serial BERT...
Page 249 Typical test times are approximately 20 minutes at 10Gbit/s and slightly more than one hour at 2.5 Gbit/s for a measurement at the 10 BER threshold with an overall confidence level better than 90%. Agilent J-BERT N4903B High-Performance Serial BERT...
Page 250: Dut Output Timing/Jitter - Procedures
– Set the Data Termination to 1.3V – Set the Clock Setup to Clock Data Recovery to get the error detector's clock from the incoming data stream. 8 Enable the pattern generator outputs by pressing the 0V (Disable) button. Agilent J-BERT N4903B High-Performance Serial BERT...
Page 251 To improve the results, you can change the measurement parameters: 1 Press the Properties button to open the Properties dialog box. 2 Use the different tabs in this dialog box to make the required settings: – Parameters tab Agilent J-BERT N4903B High-Performance Serial BERT...
Page 252: Dut Output Timing/Jitter - Reference
Set the criteria for moving to the next sample point: • Number of Compared Bits After this number of compared bits, the measurement stops for the current sample point and moves to the next one. Agilent J-BERT N4903B High-Performance Serial BERT...
Page 253 The following illustration shows a diagram with high resolution and edge resolution optimization. For the areas of the diagram with edges, additional sampling points are taken, resulting in a much better display of the signal shape: Agilent J-BERT N4903B High-Performance Serial BERT...
Page 254 • For information on the DUT Output Pass/Fail criteria, see also “Output Timing Measurement Parameters” on page 259. • For information on the Jitter Pass/Fail criteria, see also “Jitter Measurement Parameters” on page 260. Agilent J-BERT N4903B High-Performance Serial BERT...
Page 255 In the tabular view, each of the calculated values will be marked with an icon if it failed the test. The following illustration shows a DUT Output Timing/Jitter measurement that has failed the criterion for the phase margin. Agilent J-BERT N4903B High-Performance Serial BERT...
Page 256 The BER graph can be viewed in either linear and logarithmic view. The logarithmic view is shown above. The DUT Output Timing/Jitter measurement calculates the jitter histogram as the Jitter Histogram absolute of the derivative of the measured bit error rate (jitter=dBER/dt). Agilent J-BERT N4903B High-Performance Serial BERT...
Page 257 • Errors if 1s Expected To calculate the BER values if "1" is expected, but "0" received. You can calculate measurement parameters for: Calculate • 0 Errors To calculate the parameters for 0 errors. Agilent J-BERT N4903B High-Performance Serial BERT...
Page 258 Timing Units x-axis. Choose between Logarithmic and Linear to select the scale for the display's y- Scale axis. For example, a DUT Output Timing measurement displayed on a linear scale may look like this: Agilent J-BERT N4903B High-Performance Serial BERT...
Page 259 If you want to see the points that have actually been measured, choose Show Show Measured Points Measured Points. Explanation of the Numerical Results The measurement provides numerical results for: Output Timing Measurement The output timing measurement parameters are defined in the following table: Parameters Agilent J-BERT N4903B High-Performance Serial BERT...
Page 260 Total Jitter RMS The average of the left and right jitter histogram root mean squared values. • Total Jitter Peak-to-Peak Peak-to-peak value for total jitter. Calculated as the pulse period (unit interval) minus the Phase Margin. Agilent J-BERT N4903B High-Performance Serial BERT...
Page 261 <not applicable> indicates that the value could be calculated, however is not shown because quality criteria are not met. This is the case, for example, for RJ/DJ results, when the r^2 value of one or both edges is <0.75. Even though Agilent J-BERT N4903B High-Performance Serial BERT...
Page 262 The Fast Total Jitter measurement result parameters are summarized in the following list: Results • Phase Margin The period of time where the bit error rate is lower than the Total Jitter BER Threshold. • Total Jitter Peak-Peak Agilent J-BERT N4903B High-Performance Serial BERT...
Page 263: Output Levels
(DUT). The sampling delay is fixed. The error detector's decision threshold is automatically swept within a user-defined range. A direct result is the determination of the optimum decision threshold level for receiving data from the DUT with maximum confidence. Agilent J-BERT N4903B High-Performance Serial BERT...
Page 264 To remind you that the present results have not been obtained with the modified settings and that you should repeat the measurement, the result display shows a yellow bar. • Parameters that change the display of the measured data. Agilent J-BERT N4903B High-Performance Serial BERT...
Page 265: Output Levels - Procedures
PG Setup -> Data Output screen. 2 Use a shielded cable to connect the pattern generator's Data Out port and the error detector's Data In port. 3 Terminate all non-connected pattern generator output ports with 50 Ω. Agilent J-BERT N4903B High-Performance Serial BERT...
Page 266 2 Press the Properties button to open the Properties dialog box. 3 On the Parameters tab, set the Sample Threshold parameters to suitable values that fit to the expected signal levels, for example, -1.85V to -0.85V. Set the Resolution to 10 mV. Agilent J-BERT N4903B High-Performance Serial BERT...
Page 267 4 Press OK to close the Properties dialog box. 5 Press the Start button to execute the measurement. The measurement is run, and the result window shows the bit error rates measured at 100 threshold levels from -1.85V up to -850mV. Agilent J-BERT N4903B High-Performance Serial BERT...
Page 268 4 Several more options are provided on the Graph tab for you to adjust the display as you want. For instance, you can use markers for analyzing the graph or open a zoom window for viewing the details. To find more information, refer to “Graph Tab” on page 276. Agilent J-BERT N4903B High-Performance Serial BERT...
Page 269 This gives you another view of the measured data. 3 Switch to the Graph tab and select Linear Scale. The data remains the same, but a linear scale makes it easier to see the distribution. Agilent J-BERT N4903B High-Performance Serial BERT...
Page 270: Output Levels - Reference
Set the criteria for moving to the next sample point: • Number of Compared Bits After this number of compared bits, the measurement stops for the current sample point and moves to the next one. • Number of Errors Agilent J-BERT N4903B High-Performance Serial BERT...
Page 271 BER changes, and a much lower resolution (about one tenth) for measuring the regions where the BER is constant. This reduces the number of data points to 145, as shown in the figure below. Agilent J-BERT N4903B High-Performance Serial BERT...
Page 272 To set the Signal/Noise Pass/Fail criteria, see also “Noise Results” on page 278. • To set the Q Factor Pass/Fail criteria, see also “Q-factor Results” on page 279. Your setup may finally look as shown below: Agilent J-BERT N4903B High-Performance Serial BERT...
Page 273 Advanced Analysis In the following figure, you can see how errors are flagged. Agilent J-BERT N4903B High-Performance Serial BERT...
Page 274 This distribution can often be approximated by a Gaussian normal distribution. With a Gaussian marker you can measure the mean and standard deviation of the normal distribution (see also “The Gaussian Marker” on page 237 “Graph Tab” on page 276). Agilent J-BERT N4903B High-Performance Serial BERT...
Page 275 For details see “Q-factor Results” on page 279. Furthermore, the following parameters can be set on the View tab of the Properties dialog box: You can calculate measurement parameters for: Calculate • BER Threshold Agilent J-BERT N4903B High-Performance Serial BERT...
Page 276 (or your finger, if you are working directly on the Serial BERT). If you want to see the points that have actually been measured, choose Show Show Measured Points Measured Points. Agilent J-BERT N4903B High-Performance Serial BERT...
Page 277 For all parameters, pass/fail limits can be set, as indicated in the table. The level parameters are defined as follows: • High Level The High Level is the mean of the upper dBER/dTh distribution. It is calculated Agilent J-BERT N4903B High-Performance Serial BERT...
Page 278 For some of these parameters, pass/fail limits can be set, as indicated in the table. The noise parameters are defined as follows: • High Level Std. Dev. The standard deviations are derived from the dBER/dTh histogram. The High Level Standard Deviation is calculated as: Agilent J-BERT N4903B High-Performance Serial BERT...
Page 279 Threshold. Q-factor Results The Q-factor result parameters are summarized in the following table: Table 29 Parameter Name Pass/Fail Q Factor Q Optimum Threshold min/max Q Residual BER Q High Level Q High Level Std.Dev Agilent J-BERT N4903B High-Performance Serial BERT...
Page 280 • Q Residual BER The Q Residual BER is the expected BER at the Optimum Decision Threshold. It is calculated as: BER = Numbers below 1e-255 are expressed as zero. • Q High Level Agilent J-BERT N4903B High-Performance Serial BERT...
Page 281 If the R value falls below 0.75, the Q-factor calculations are not applicable. • Q Low Level The Q Low Level is the mean, calculated from the linear regression curve for the low level data: Agilent J-BERT N4903B High-Performance Serial BERT...
Page 282 The Q-factor method and the related calculations have been published under Margin N O T E Measurements in Optical Amplifier Systems by Neal S. Bergano, F. W. Kerfoot, and C. R. Davidson in IEEE Photonics Technology Letters, Vol. 5, No. 3, March 1993. Agilent J-BERT N4903B High-Performance Serial BERT...
Page 283 1 or 0 rail. For the complementary error function erfc(x) = x 2 p an inverse logarithmic approximation exists: x - 0.0162 x 1.192 - 0.6681 erfc(x) where x = Log(BER). Agilent J-BERT N4903B High-Performance Serial BERT...
Page 284 The following calculations are performed for the high and low level data: where n is the number of respective data points. The results of the linear regression are displayed in the QBER vs. Threshold graph. Agilent J-BERT N4903B High-Performance Serial BERT...
Page 285 On the other hand, such a comparison may make it easier to understand the Comparison of the Results dependencies. If you set the BER Threshold to a position that gives you only a few data points, you will find: • The Q-factor is relatively high. Agilent J-BERT N4903B High-Performance Serial BERT...
Page 286 Gaussian shape. It will not fit, for example, if the received signal is dominated by cross-talk or modal noise. Agilent J-BERT N4903B High-Performance Serial BERT...
Page 287: Eye Opening
In detail, the measurement is not that simple and more precise as it derives the contour of the eye from the bit error rates that have been measured. Three Available Views The Eye Diagram can be visualized in three different ways: • Contour Plot Agilent J-BERT N4903B High-Performance Serial BERT...
Page 288 BER. This is useful to get an immediate visual impression of the distribution of the BER in the eye diagram. • Equal BER at BER threshold This graph displays only one curve for the chosen bit error rate threshold. Agilent J-BERT N4903B High-Performance Serial BERT...
Page 289: Eye Opening - Procedures
This requires the following steps: • Preparing the measurement (see “How to Prepare the Eye Opening Measurement” on page 290) • Executing the measurement (see “How to Execute the Eye Opening Measurement” on page 291) Agilent J-BERT N4903B High-Performance Serial BERT...
Page 290 8 Press Sync Now and then Auto Align to find the optimum sampling point. Check that the synchronization and the alignment were successful. None of the error indicators should show red. The resulting BER should be zero. Agilent J-BERT N4903B High-Performance Serial BERT...
Page 291 – Pass/Fail tab These settings determine whether the calculated results are recognized as passed or failed. However, a new test run is not required when doing changes here. See “Pass/Fail Tab” on page 296 for details. Agilent J-BERT N4903B High-Performance Serial BERT...
Page 292 If you have a mouse connected to your Serial BERT, you can add a color to the color bar or change a color: • From the context menu of the color bar, choose from the following display options: Table 30 Option Description Gradient Agilent J-BERT N4903B High-Performance Serial BERT...
Page 293 If no slider for the BER threshold is displayed, make sure that you have enabled the N O T E BER Threshold option on the View tab and that a suitable BER is entered. Agilent J-BERT N4903B High-Performance Serial BERT...
Page 294: Eye Opening - Reference
Additionally, some information is provided to explain the theoretical background behind. Properties that can be specified on the various tabs of the Properties dialog box: Agilent J-BERT N4903B High-Performance Serial BERT...
Page 295 This can greatly improve the results without dramatically increasing the duration of the test. Set the criteria for the sample threshold: • Resolution Specifies how many measurement points are taken within the sample voltage range. Enter the value in mV. Agilent J-BERT N4903B High-Performance Serial BERT...
Page 296 You can set several pass/fail limits. For an explanation of the Eye Opening Pass/ Fail criteria, see “Measurement Parameters” on page 301. Agilent J-BERT N4903B High-Performance Serial BERT...
Page 297 In the tabular view, each of the calculated values will be marked with an icon if it failed the test. The following illustration shows an Eye Opening measurement that has failed the criteria for the eye opening voltage. Agilent J-BERT N4903B High-Performance Serial BERT...
Page 298 This plot visualizes the BER by a continuous color gradient. This is useful to get Pseudo Color Plot an immediate visual impression of the distribution of the BER in the eye diagram. Agilent J-BERT N4903B High-Performance Serial BERT...
Page 299 To calculate the parameters for 0 errors. • BER Threshold To calculate the parameters for the given BER threshold. The BER threshold influences all parameters of the Eye Opening measurement. You can also drag Agilent J-BERT N4903B High-Performance Serial BERT...
Page 300 If no slider for the BER threshold is displayed, make sure that you have enabled the N O T E BER Threshold option on the View tab and that a suitable BER is entered. Agilent J-BERT N4903B High-Performance Serial BERT...
Page 301 BER threshold), the numerical results cannot be calculated. In this case, the software will issue a warning message. If this happens, you should first of all check the settings of the low and high decision threshold voltages. Agilent J-BERT N4903B High-Performance Serial BERT...
Page 302: Error Location Capture
This feature can be used to find rare or random errors. A DUT could have problems handling long series of zeroes. Error Location Capture can be used to locate the bit errors in such cases. Agilent J-BERT N4903B High-Performance Serial BERT...
Page 303 Requirements” on page 228: • Only memory-based patterns with a unique 48-bit pattern (detect word) are allowed. • No alignment features can run during error location capture: Auto Align, 0/1 Threshold Center, Data Center Agilent J-BERT N4903B High-Performance Serial BERT...
Page 304: Error Location Capture - Procedures
7 Press Sync Now and then Auto Align to find the optimum sampling point. Check that the synchronization and alignment were successful. None of the error indicators should show red. The resulting BER should be zero. Agilent J-BERT N4903B High-Performance Serial BERT...
Page 305: Error Location Capture - Reference
The Error Location Capture measurement compares the expected pattern and the pattern that was actually received, and shows the received pattern with the errored bits marked. Elements of the User Interface The following buttons help you to analyze the results: • Hex / Bin Agilent J-BERT N4903B High-Performance Serial BERT...
Page 306 • Position: The position of the current errored bit is shown. • Hex/Bin: This field indicates how the data is shown (bin or hex format). Agilent J-BERT N4903B High-Performance Serial BERT...
Page 307: Fast Eye Mask
Measuring the eye openings with an oscilloscope used to be a time-consuming procedure. With the Fast Eye Mask measurement of the Serial BERT, pass/fail information can be obtained within seconds. Agilent J-BERT N4903B High-Performance Serial BERT...
Page 308 The last row shows the measured bit error rates at these points. • The Relative Time of the measured points refers to the actual sampling point. If synchronization and auto-alignment were successful, the current sampling point is the optimum sampling point. Agilent J-BERT N4903B High-Performance Serial BERT...
Page 309: Fast Eye Mask - Procedures
Preparing the Fast Eye Mask Measurement. (See “How to Prepare the Fast Eye Mask Measurement” on page 310 • Executing the Fast Eye Mask Measurement. (See “How to Execute the Fast Eye Mask Measurement” on page 310 Agilent J-BERT N4903B High-Performance Serial BERT...
Page 310 How to Execute the Fast Eye Mask Measurement To run the Fast Eye Mask measurement: 1 Switch to the Analysis panel and then press the Fast Eye Measurement icon. 2 Press the Start button to execute the measurement. Agilent J-BERT N4903B High-Performance Serial BERT...
Page 311: Fast Eye Mask - Reference
The Fast Eye Mask measurement returns the results in a numerical form. The following sections provide explanations of the measured parameters and the display options that are specific to this measurement. Properties that can be specified on the various tabs of the Properties dialog box: Agilent J-BERT N4903B High-Performance Serial BERT...
Page 312 You specify the thresholds for the measurement points relative to the threshold voltage of the actual sampling point. – Percentage You specify the thresholds for the measurement points as a percentage of the current eye opening voltage of the error detector. Agilent J-BERT N4903B High-Performance Serial BERT...
Page 313 The Fast Eye Mask measurement has only one pass/fail condition: The bit error rate. If desired, enable the BER Threshold and set a suitable threshold. Agilent J-BERT N4903B High-Performance Serial BERT...
Page 314 To display the errors if "1" is expected, but "0" received. You can set the Timing Unit for the display of the relative time of the measurement Grid points on the Parameters tab. Choose between Unit Interval and Seconds to select the unit. Agilent J-BERT N4903B High-Performance Serial BERT...
Page 315: Eye Diagram
The Eye Diagram, and the table of Automated Eye Parameter Measurement form simultaneously. They become more precise with the increasing number of measured bits. The following graph shows how the Eye Diagram has been integrated on the J- BERT N4903A High-Performance Serial BERT. Agilent J-BERT N4903B High-Performance Serial BERT...
Page 316 ‘smooth waveform’ quickly generates a high resolution graph. The waveform is displayed in an incremental way, showing the coarse picture quickly, and then refining it further. Agilent J-BERT N4903B High-Performance Serial BERT...
Page 317 BER in the same color. Initially all the BER values on the legend are struck across. When the contour is measured, the BER value changes into normal font; and when the contour is extrapolated the BER value changes into Agilent J-BERT N4903B High-Performance Serial BERT...
Page 318 The mask violations are marked in green. A consolidated report of the test is available on the left bottom of the graph. The user can turn off the mask computation by pressing the “stop” button. Agilent J-BERT N4903B High-Performance Serial BERT...
Page 319 Eye behavior, and they depend on the parameters set in the View Tab. These results are displayed in a tabular form as shown below: In case you want to see a specific set of Eye Measurements you can select it on the Eye Measurements tab. Agilent J-BERT N4903B High-Performance Serial BERT...
Page 320: Eye Diagram - Procedures
6 Specify the logic levels and the bit rate for the pattern generator setup. For example, select ECL levels and a clock speed of 1250 MHz. This corresponds to a clock period of 0.8 ns. Agilent J-BERT N4903B High-Performance Serial BERT...
Page 321 2 Click the Start button to execute the measurement. The measurement runs, and the eye diagram along with the Automated Eye Parameter Measurement get updated constantly. The following graph shows the eye diagram. 3 To stop the measurement click on Abort. Agilent J-BERT N4903B High-Performance Serial BERT...
Page 322 The Parameter settings used for the measurement can be changed only when the measurement is not running, and if the settings are changed, then you will have to re-run the measurement. (Refer to “Parameters” on page for the detailed options). – View tab Agilent J-BERT N4903B High-Performance Serial BERT...
Page 323 (Refer to “View” on page for the detailed options) – Graph tab The graph settings give the display parameters like timing units, waveform, contour, grid and markers. Agilent J-BERT N4903B High-Performance Serial BERT...
Page 324 Advanced Analysis – Eye Measurements tab The Eye Measurements tab lists out all the measurements. The user can select specific results. Agilent J-BERT N4903B High-Performance Serial BERT...
Page 325 2 Select Show Maker Lines 3 Apply Setting This enables the markers, and a marker readout button appears on the top left corner. You also have an option to Reset Markers to their original position. Agilent J-BERT N4903B High-Performance Serial BERT...
Page 326 How to Run the Mask Measurement? To run the Mask Measurement, the Eye Diagram measurement must be running. 1 Click on the Mask tab 2 Click Load button 3 Select a Mask File. 4 Select a Mask Alignment. Agilent J-BERT N4903B High-Performance Serial BERT...
Page 327 Region Number The region number is an integer that defines a mask violation area (or polygon). You can specify 1 to a maximum of 3 regions in a mask file. Example to Region Number: Agilent J-BERT N4903B High-Performance Serial BERT...
Page 328 0 and 1 coordinates of the mask X and Y- axes. Commands listed in the setup area are executed as part of the mask data load process. Example to Mask Setup: :MTES:SCAL:YTRACK OFF :MTES:SCAL:Y1 -0.65 :MTES:SCAL:Y2 +0.65 :MTES:SCAL:XDEL 312.5E-12 :MTES:AMET NRZEYE Agilent J-BERT N4903B High-Performance Serial BERT...
Page 329 2 Enter your notes in the drop down text box. This gives the timestamps of the comments entered. It’s a scrollable editor where your latest comments are entered at the end. How to Save and Recall To Save the following measurements: • Eye Diagram Agilent J-BERT N4903B High-Performance Serial BERT...
Page 330 1 Click on the Analysis Menu 2 Click on ‘Load Measurement’ How to Export Fetched Data? You can export various counters to an exported file location. 1 Click on Analysis Menu 2 Click on ‘Export Data’ Agilent J-BERT N4903B High-Performance Serial BERT...
Page 331 You can select the ‘Format’, ‘Save to File’ and ‘Error Options’ as per requirements. The ‘Save to File’ option specifies, either saving only the BER values, or saving the BER, the Compared Bits, and the Errors. Agilent J-BERT N4903B High-Performance Serial BERT...
Page 332: Eye Diagram - Reference
With ‘Secs’, the measurement runs for the specified time, and the measurement automatically restarts showing only the refined eye diagram. To stop the measurement, click the abort button. Center to Sets the transition of the eye on the plot • Middle of eye Agilent J-BERT N4903B High-Performance Serial BERT...
Page 333 Set the criteria for eye boundaries. Total is 100% of the display screen. These are applied for the level related parameters, for example, 0-level, 1-level, Signal to Noise ratio, Eye Amplitude, and so forth. • Left Boundary Agilent J-BERT N4903B High-Performance Serial BERT...
Page 334 Is used to convert voltage level into power. Power Unit • Output will be displayed in dBm. power value[dBm]=10*log(power value[W]/1mW) • Output will be displayed in Watt Extinction Ratio Unit Set the criteria for the Extinction Ratio Unit • Ratio Agilent J-BERT N4903B High-Performance Serial BERT...
Page 335 Show Legend This shows the list of BER values. Grid • Show Grid The 353pxl X 289pxl screen is divided into a 10 X 8 grid. This parameter adds a grid to the screen. Agilent J-BERT N4903B High-Performance Serial BERT...
Page 336 With the logic levels track selected, the mask regions are bound together, and move together with a fixed amplitude. Position (pos) gives the timing displacement, and dT gives the delta time offset. Mask Run Control Set Mask Run Control: Agilent J-BERT N4903B High-Performance Serial BERT...
Page 337 Transition Time of the View Tab. The two options are 10/90 and 20/80. Sample Count The number of points measured for the eye diagram. If persistence, ‘infinite’, is enabled, the value will gradually increase. Agilent J-BERT N4903B High-Performance Serial BERT...
Page 338 Configure Measurement dialog box. These settings determine what portion of the eye will be measured. Eye Amplitude The difference between the logic 1 level and the logic 0 level. Agilent J-BERT N4903B High-Performance Serial BERT...
Page 339 Full width of the histogram at the eye crossing point with respect to BER threshold. Note: The Jitter P-P is calculated according to the BER Threshold set in the BERT from Calculate Measurement Parameters of the View Tab. Agilent J-BERT N4903B High-Performance Serial BERT...
Page 340 Extinction ratio is the ratio of the 1 level power and the 0 level power of an eye diagram. Note: The Extinction Ratio is calculated using the Dark Level and Conversion Gain of the View Tab. Agilent J-BERT N4903B High-Performance Serial BERT...
Page 341 0 bit. Average Power The mean of level 0 power and the level 1 power. Note: The Average Power is calculated using the Dark Level and Conversion Gain of the View Tab. Agilent J-BERT N4903B High-Performance Serial BERT...
Page 342: Spectral Jitter
The Spectral Jitter measurement provides a method for investigating the spectrum of the jitter, i.e. its power distribution over frequency. Deterministic jitter can be caused by repetitive data patterns. It can also be caused by internal or external periodic effects. Agilent J-BERT N4903B High-Performance Serial BERT...
Page 343 The number of captured data points is adjustable. While the measurement is running, correct and incorrect data is captured. The resulting records contain the captured data and the corresponding error information. Agilent J-BERT N4903B High-Performance Serial BERT...
Page 344 The histogram of pure random jitter shows its Gaussian distribution, as illustrated in the following figure: Deterministic jitter periodically adds and subtracts a delay to/from the received signal. Jitter caused by a square wave or on/off signal has produced the following histogram: Agilent J-BERT N4903B High-Performance Serial BERT...
Page 345 The Spectral Jitter measurement provides: • A graphical view of power vs. frequency. This makes it easy to identify prominent spectral jitter components. You can adjust the horizontal and vertical axes according to your needs. Agilent J-BERT N4903B High-Performance Serial BERT...
Page 346 Let us also assume, this signal is overlaid by a periodic jitter source with sinusoidal characteristics. Now we sample the incoming signal at the transition point (-0.5 UI from the optimum sampling point). The result is illustrated in the figure below. Agilent J-BERT N4903B High-Performance Serial BERT...
Page 347 If random data is used, the average bit error rate at the left-hand side of the jitter region is 0.5. The bit error rate at the right-hand side of the jitter region is 0. We therefore expect a bit error rate around 0.25. Agilent J-BERT N4903B High-Performance Serial BERT...
Page 348 Communication Transceivers", IEEE Design and Test of Computers, Jan-Feb 2002 The error record contains a bipolar, rectangular signal. If such a signal is periodic, FFT results you can expect a spectrum as illustrated below. Agilent J-BERT N4903B High-Performance Serial BERT...
Page 349 FFT assumes that the time record contains a representative section of an endless Leakage and Windowing periodic signal. It assumes that time records can be seamlessly concatenated. If this is not the case, a phenomenon called leakage occurs. Agilent J-BERT N4903B High-Performance Serial BERT...
Page 350 An FFT window is a filter that sets the beginning and end of the time record smoothly to zero. Such records can be seamlessly concatenated. When you are using a window, please note: • No window removes leakage completely. Agilent J-BERT N4903B High-Performance Serial BERT...
Page 351: Spectral Jitter - Procedures
7 Enable the pattern generator outputs by pressing the 0V (Disable) button. 8 Also make sure that the error detector derives its clock from the incoming data stream using Clock Data Recovery. See “Clock Setup - Procedures” on page for details. Agilent J-BERT N4903B High-Performance Serial BERT...
Page 352 To improve the results, you can change the measurement parameters: 1 Press the Properties button to open the Properties dialog box. 2 Use the different tabs in this dialog box to make the required settings: – Parameters tab Agilent J-BERT N4903B High-Performance Serial BERT...
Page 353: Spectral Jitter - Reference
A smaller number reduces the duration of the Spectral Jitter measurement and its precision. A larger number increases the measurement duration but also the frequency resolution of the measured spectral components. The frequency resolution of the measurement is: Agilent J-BERT N4903B High-Performance Serial BERT...
Page 354 Set the FFT window for the FFT Calculation. The following windows are provided: • Uniform • Hanning (sometimes also called Hann) • Hamming • Blackman The "uniform" window is no window at all. This setting supplies the original error record to the FFT. Agilent J-BERT N4903B High-Performance Serial BERT...
Page 355 The Pass/Fail tab of the Properties dialog box allows you to specify the criteria to decide whether the DUT passes or fails the test. You can change pass/fail criteria without rerunning a test. The software only uses the criteria to rate the results of a measurement. Agilent J-BERT N4903B High-Performance Serial BERT...
Page 356 In the tabular view, each of the calculated values will be marked with an icon if it failed the test. The following illustration shows a Spectral Jitter measurement that has failed the criterion for the Bit Error Rate. Agilent J-BERT N4903B High-Performance Serial BERT...
Page 357 The View tab allows you to change the power scale from linear to dB. The dB scale is a logarithmic scale. The dB scale allows you to examine the whole power range. The following figure shows an example of a double logarithmic display. Agilent J-BERT N4903B High-Performance Serial BERT...
Page 358 Up to 16 pairs can be calculated and displayed. Graph Tab On the Graph tab, you can use the several options to optimize the graphical display according to your needs. Agilent J-BERT N4903B High-Performance Serial BERT...
Page 359 The Frequency and total power for up to the 16 frequencies with the highest total power. You can set the number of top frequencies to be evaluated in the View tab (see “View Tab” on page 256 for details). Agilent J-BERT N4903B High-Performance Serial BERT...
Page 360 Advanced Analysis Agilent J-BERT N4903B High-Performance Serial BERT...
Page 361: Evaluating Results
Agilent J-BERT N4903B High-Performance Serial BERT User Guide Evaluating Results Evaluating Results - Concepts The Serial BERT offers several different kinds of tests that can be run: • Instantaneous Measurements This type of measurements is used to monitor the instantaneous "BER" / "8B/ 10B Comparison"...
Page 362 Adjust the sampling point to see the effect on the "BER" / "8B/10B Comparison" / "Bit Comparison without PCIe3 SKPOS" / "Bit Comparison without USB3.1 SKPOS". See “Sampling Point Setup - Concepts ” on page for details. • Make modifications to your device setup. Agilent J-BERT N4903B High-Performance Serial BERT...
Page 363: Instantaneous Measurements - Procedures
Error Add button in the top right corner of the screen. When inserting an error, the BER/SER/FER/FSR/ISR/DER/cBER should increase for a short time and then return to the initial value. Agilent J-BERT N4903B High-Performance Serial BERT...
Page 364 1 Listen to the Bit Comparison without USB3.1 SKPOS warning tones. See “Audio Signals - Procedures” on page 225 for details. 2 View the Bit Comparison without USB3.1 SKPOS Results window, which is described in “BER Results Window” on page 366. Agilent J-BERT N4903B High-Performance Serial BERT...
Page 365 10B Comparison" / "Bit Comparison without PCIe3 SKPOS" / "Bit Comparison without USB3.1 SKPOS". You can determine what adjustments improve or degrade the "BER" / "8B/10B Comparison" / "Bit Comparison without PCIe3 SKPOS" / "Bit Comparison without USB3.1 SKPOS". Agilent J-BERT N4903B High-Performance Serial BERT...
Page 366: Instantaneous Measurements - Reference
Error Count/Accum Error Count The BER bar below the main menu bar also displays the actual BER. You can drag N O T E the small yellow alarm threshold mark to change the BER Alarm Threshold. Agilent J-BERT N4903B High-Performance Serial BERT...
Page 367 - if no accumulation is running - the results of the most recent accumulation. This enables you to monitor real-time SER behavior as you do things such as to manually adjust the sampling point, to add errors, or to make adjustments to your device. Agilent J-BERT N4903B High-Performance Serial BERT...
Page 368 Click this button to toggle between FER or AccumFER results. Accumulated/Actual Button This area displays the actual frame error count or cumulative frame error count. Error Count/Accum Error Count cBER Results Window This window displays the actual (cBER) or cumulative (AccumcBER) cBER results: Agilent J-BERT N4903B High-Performance Serial BERT...
Page 369 You can click Accumulated/Actual button to toggle between cBER or AccumcBER results. The Error Count/Accum Error Count area displays the actual error count or cumulative error count. FSR Results Window This window displays the actual (FSR) or cumulative (AccumFSR) FSR results: Agilent J-BERT N4903B High-Performance Serial BERT...
Page 370 Accumulated/Actual Button This area displays the actual filler symbol error count or cumulative filler symbol Error Count/Accum Error Count count. DER Results Window This window displays the actual (DER) or cumulative (AccumDER) DER results: Agilent J-BERT N4903B High-Performance Serial BERT...
Page 371 Accumulated/Actual Button This area displays the actual illegal disparity change count or cumulative illegal Error Count/Accum Error Count disparity change count. ISR Results Window This window displays the actual (ISR) or cumulative (AccumISR) ISR results: Agilent J-BERT N4903B High-Performance Serial BERT...
Page 372 The BER bar displays the BER calculated upon a period of 200 ms. BER bar You can drag the yellow alarm threshold mark to change the BER Alarm Threshold. The SER bar displays the SER calculated upon a period of 200 ms. SER bar Agilent J-BERT N4903B High-Performance Serial BERT...
Page 373 Loss of the error detector's clock signal • Loss of the pattern generator's clock signal • 10B symbol alignment is not done or is lost • Loaded patterns have some disparity errors or contains invalid symbols Agilent J-BERT N4903B High-Performance Serial BERT...
Page 374 The Show Error Messages button displays the error messages. It uses the color Show Error Messages codes to indicate the following possible states: • No error messages: The button will be in disable state. • New/unread errors: The triangle icon on the button will turn red. Agilent J-BERT N4903B High-Performance Serial BERT...
Page 375 Accumulation Setup dialog box. For more information, see “How to Run Accumulated Measurements” on page 377. The PG and ED pattern types are displayed here for your reference. Pattern Types Agilent J-BERT N4903B High-Performance Serial BERT...
Page 376: Accumulated Measurements
The accumulation period should be long enough to make a statistically valid BER measurement. See “Test Times and Confidence Levels” on page 27 for details. Agilent J-BERT N4903B High-Performance Serial BERT...
Page 377: Accumulated Measurements - Procedures
If you selected a manual test, it will run until you stop it manually. • Press the Stop Accum button on the front panel to stop the test immediately. Errors are only counted when the signal at the Gate In port is low. N O T E Agilent J-BERT N4903B High-Performance Serial BERT...
Page 378: Accumulated Measurements - Reference
Data from the current and all previous accumulation periods is available in the N O T E measurement log files, if correctly set up. This window contains a graph and five tables: Agilent J-BERT N4903B High-Performance Serial BERT...
Page 379 BER data. You can continue to click on the graph until you have zoomed to the maximum. The point you click will appear in the middle of graph. You can press the back button (left arrow) to zoom out again. Agilent J-BERT N4903B High-Performance Serial BERT...
Page 380 The ratio of the errored 1's count to the bit count is displayed here to 4 significant digits. • Errored 1's Count The number of logic 1's measured as logic 0's during the accumulation period is displayed here. Agilent J-BERT N4903B High-Performance Serial BERT...
Page 381 Incomplete blocks of less than 60 seconds are treated as complete blocks of 60 seconds. • Errored Seconds The ratio of the errored seconds in the available time to the total number of seconds in the available time, expressed as a percentage. Agilent J-BERT N4903B High-Performance Serial BERT...
Page 382 For repeat mode, this percentage is recalculated each time the accumulation period repeats. • Accumulation Mode The type of accumulation mode is displayed here. The mode can be Manual, Single, or Repeat. Agilent J-BERT N4903B High-Performance Serial BERT...
Page 383 Statistically, every other burst would be correctly synchronized. In this case, it is recommended that you redefine the pattern. This error can only occur with memory-based patterns. – Unknown Agilent J-BERT N4903B High-Performance Serial BERT...
Page 384 The Accumulated Results window for 8B/10B Comparison contains a graph and two tables: The Accumulated Results window for 8B/10B Comparison does not contain tables N O T E for G.821Measurement, Internal Results and Burst Results. Agilent J-BERT N4903B High-Performance Serial BERT...
Page 385 The following is the expression used to calculate the Calc Bit Error Ratio: • Calc Bit Error Count The Calc Bit Error Count is is displayed here which is equal to Symbol Error Count. Agilent J-BERT N4903B High-Performance Serial BERT...
Page 386 • Filler Symbol Count (Filler symbol counter) The total number of filler symbol count received in a time interval is displayed here. The following is the expression used to calculate the Filler Symbol Count: Agilent J-BERT N4903B High-Performance Serial BERT...
Page 387 Data Rate Ratio The ratio of the number of filler symbol count to the expected filler symbol count received in the current (or last completed) accumulation period, specified by the gate period is displayed here. Agilent J-BERT N4903B High-Performance Serial BERT...
Page 388 Comparing SATA FER counter with the Serial BERT shows that due to errors at the receiver input, DUTs may drop a complete symbol. In such situation, a protocol analyzer which only calculates CRC (Cyclic Redundency Check) reports Agilent J-BERT N4903B High-Performance Serial BERT...
Page 389 The Accumulated Results window for Bit Comparison without PCIe3 SKPOS contains a graph and two tables: The Accumulated Results window for Bit Comparison without PCIe3 SKPOS does N O T E not contain tables for G.821Measurement, Internal Results and Burst Results. Agilent J-BERT N4903B High-Performance Serial BERT...
Page 390 The total number of Auto Re-Sync Count received in a time interval is displayed here. Accumulation Parameters for Bit Comparison without PCIe3 SKPOS For detailed information on "Bit Comparison without PCIe3 SKPOS" accumulation parameters, see “Accumulation Parameters” on page 382. Agilent J-BERT N4903B High-Performance Serial BERT...
Page 391 In addition to the values displayed in the BER Accumulated Results (see “Accumulated Results” on page 380), the following additional value is listed: • Auto Resync Counter The total number of Auto Re-Sync Count received in a time interval is displayed here. Agilent J-BERT N4903B High-Performance Serial BERT...
Page 392: Eye Measurements
This will allow you to see the eye margin at specific BERs and construct basic eye contour information. 3 Change the sampling point in the Sampling Point Setup window. See “Sampling Point Display” on page 202 for details. Agilent J-BERT N4903B High-Performance Serial BERT...
Page 393: Eye Measurements - Reference
The upper and lower eye edges are determined by the user- defined BER threshold. Different BER thresholds will produce different eye height results. Upper eye edge Eye height Lower eye edge Agilent J-BERT N4903B High-Performance Serial BERT...
Page 394 The alignment BER threshold is displayed here. This threshold was used to define the eye edges and the above eye results. • Delta Error Ratio The BER measured during the previous 200 ms is displayed here. Agilent J-BERT N4903B High-Performance Serial BERT...
Page 395: Jitter Tolerance Tests
Agilent J-BERT N4903B High-Performance Serial BERT User Guide Jitter Tolerance Tests Jitter Tolerance Tests - Concepts This chapter refers only to Serial BERT instruments on which the calibrated and N O T E integrated jitter injection option J10 is installed.
Page 396 The Serial BERT provides the Interference Channel option J20 to simulate ISI. For more information see • “Intersymbol Interference” on page 399 Level Noise Level noise affects the voltage amplitude of the eye opening. Agilent J-BERT N4903B High-Performance Serial BERT...
Page 397 This kind of jitter has a Gaussian distribution over time. Theoretically, the Gaussian distribution stretches from -∞ to +∞. In practice, the amplitude is defined by the crest factor (p-p amplitude = sigma × crest factor) Agilent J-BERT N4903B High-Performance Serial BERT...
Page 398 Periodic Jitter Periodic jitter (PJ) is generally picked up from other periodic sources. Rectangular jitter may be caused, for example, by a switching power supply. It has Rectangular Jitter a distribution as shown below. Agilent J-BERT N4903B High-Performance Serial BERT...
Page 399 Triangular jitter has a uniform jitter distribution. Intersymbol Interference Intersymbol interference (ISI) is caused by bandwidth limitations of cables and backplanes. It cuts off higher frequencies and hence changes the shape of the eye opening. Agilent J-BERT N4903B High-Performance Serial BERT...
Page 400 For jitter tolerance tests, amplitude modulation is most often simulated by modulating the data output with a sinewave signal. This is called Sinusoidal Interference (SI). Total Jitter Total jitter is the sum of all kinds of jitter. Agilent J-BERT N4903B High-Performance Serial BERT...
Page 401 Spread Spectrum Clock (rSSC), sinusoidal jitter (SJ), two periodic jitter sources (PJ-1 and PJ-2), bounded uncorrelated jitter (BUJ), Random Jitter (RJ) and spectrally distributed Random Jitter (sRJ), which is composed by using the BUJ Agilent J-BERT N4903B High-Performance Serial BERT...
Page 402 (ISI) with or without sinusoidal interference (SI). This is a hardware module that can be plugged into the instrument. It has two ports, P1/P1 and P2/P2. Both can be connected single-ended or differentially. Agilent J-BERT N4903B High-Performance Serial BERT...
Page 403 ISI must be enabled if sinusoidal interference shall be added to the signal. In this case, the minimum trace is longer (refer to the technical specifications). Data can be input by connecting the pattern generator's Data Out port to either P1 or P2. Agilent J-BERT N4903B High-Performance Serial BERT...
Page 404: Jitter Setup
• Jitter configuration area • Jitter setup area • Jitter switch area Jitter On/Off Button and Delay Line Status Area The Jitter On/Off button allows you to globally enable or disable the jitter generation. Agilent J-BERT N4903B High-Performance Serial BERT...
Page 405 The Jitter Setup area consists of seven colored rows that keep you informed about the present jitter composition of: • Sinusoidal Jitter • Spread Spectrum Clock • Residual Spread Spectrum Clock • Periodic Jitter 1 • Periodic Jitter 2 • Bounded Uncorrelated Jitter Agilent J-BERT N4903B High-Performance Serial BERT...
Page 406 Define whether the corresponding jitter source is applied to the data and/or the clock output. It is not possible to disconnect the jitter sources from both outputs. However, it can N O T E be done by disabling the corresponding jitter sources. Agilent J-BERT N4903B High-Performance Serial BERT...
Page 407: Jitter Setup - Procedures
The Jitter On/Off button has no impact on SSC. If spread spectrum clocking is N O T E enabled, it continues, even if the Jitter On/Off button is off. Agilent J-BERT N4903B High-Performance Serial BERT...
Page 408 3 Define the delay between 220ps delay line jitter on Clock and Data. The delay has to be defined in steps of 100ps. The given value will automatically N O T E round to the next valid value. Agilent J-BERT N4903B High-Performance Serial BERT...
Page 409 2 Set the most commonly used parameter (typically Amplitude and Frequency) directly. 3 Press Edit button to access all parameters of the corresponding jitter type. This opens a window which allows you to set all parameters available for the given jitter type. Agilent J-BERT N4903B High-Performance Serial BERT...
Page 410 This section shows you how to specify the Jitter components for PJ Sweep. You will not see the parameter (Amplitude and Frequency) in case the PJ Sweep is N O T E already on. Agilent J-BERT N4903B High-Performance Serial BERT...
Page 411 – Sweep Time – Nr. of Steps For more information on parameters, see “Periodic Jitter 2 – Constant Amplitude Sweep Parameters” on page 423. 5 Activate Variable Amplitude Sweep (press Variable Amplitude Sweep button). Agilent J-BERT N4903B High-Performance Serial BERT...
Page 412 But this is just an indication. You can still add or change internal jitter components. The external jitter range is automatically updated when you add, change, or switch off one of the internal sources. Agilent J-BERT N4903B High-Performance Serial BERT...
Page 413: Jitter Setup - Reference
Jitter Configuration Use these radio buttons to select: • SSC or rSSC • RJ and BUJ or sRJ Jitter Distribution Use these switches to define whether the jitter shall be applied to clock and/or data. Agilent J-BERT N4903B High-Performance Serial BERT...
Page 414 This switch can be pressed to switch the source of periodic jitter (1 and 2) and BUJ to either the 610ps or the 220ps delay line. The 610ps delay line cannot be used for data rates above 3.37 GHz. N O T E Agilent J-BERT N4903B High-Performance Serial BERT...
Page 415 Jitter Setup Area The Jitter Setup area shows the present jitter composition. To become active, jitter sources must be switched on (by enabling the corresponding button) and must at least have an Amplitude greater than zero. Agilent J-BERT N4903B High-Performance Serial BERT...
Page 416 Out, Clock Out, Aux Data Out, and Trigger/Ref Clock Out ports. The spread spectrum clock is characterized by: • Deviation • Frequency • Type • Profile If the deviation type centerspread is selected, the deviation can be changed in two different ways: Agilent J-BERT N4903B High-Performance Serial BERT...
Page 417 The deviation Frequency. The SCC provides the frequency range of 10 kHz – 100 kHz. Type You can click on the corrosponding button to choose among Downspread, Centerspread and Upspread deviation type. The green LED on the button indicates the currently selected deviation type. Agilent J-BERT N4903B High-Performance Serial BERT...
Page 418 Arbitrary profile. The green LED on the button indicates the currently selected profile. For Arbitary profile, you need to specify the Arbitary Waveform file. To do so, click on the Browse button and select the file from the shown list. Agilent J-BERT N4903B High-Performance Serial BERT...
Page 419 Residual Spread Spectrum Clock is characterized by: • Amplitude (peak-to-peak) • Frequency There is a dependency between frequency and acceptable amplitude. A graph indicates whether the chosen setting of frequency and amplitude is acceptable. Agilent J-BERT N4903B High-Performance Serial BERT...
Page 420 Amplitude The maximum peak-to-peak Amplitude is limited by the chosen jitter frequency. Frequency Note that high-frequency sinusoidal data jitter can be generated by the Periodic Jitter function or by applying an External jitter source. Agilent J-BERT N4903B High-Performance Serial BERT...
Page 421 Periodic Jitter 2 Parameters The Periodic Jitter 2 has the following modes: • Periodic Jitter 2 – Constant Jitter • Periodic Jitter 2 – Constant Amplitude Sweep • Periodic Jitter 2 – Variable Amplitude Sweep Agilent J-BERT N4903B High-Performance Serial BERT...
Page 422 N O T E enabled. The setting for the jitter Amplitude is shared with the Constant Amplitude Sweep N O T E mode. A graph indicates whether the chosen setting of frequency and amplitude is tolerable. Agilent J-BERT N4903B High-Performance Serial BERT...
Page 423 The Periodic Jitter 2 – Constant Amplitude Sweep is characterized by: • Amplitude • Frequency Range • Waveform • Sweep Time • Nr. of Steps A graph indicates whether the chosen setting of frequency and amplitude is tolerable. Agilent J-BERT N4903B High-Performance Serial BERT...
Page 424 The Periodic Jitter 2 – Variable Amplitude Sweep is characterized by: • Standard • Waveform • Sweep Time • Nr. of Steps • Step Distance A graph indicates whether the chosen setting of frequency and amplitude is tolerable. Agilent J-BERT N4903B High-Performance Serial BERT...
Page 425 You can use this drop-down list to specify whether the frequency steps are log equidistant (EQUidistant) along the periodic jitter curve or a frequency step matches a corner frequency on the periodic jitter curve. Bounded Uncorrelated Jitter Parameters Bounded uncorrelated jitter is characterized by • Data rate Agilent J-BERT N4903B High-Performance Serial BERT...
Page 426 The maximum peak-to-peak Amplitude is limited by the free capacity of the 20 ps delay line. PRBS The PRBS polynomial can be chosen from a list. Available are eight polynomials, from 2 -1 up to 2 Agilent J-BERT N4903B High-Performance Serial BERT...
Page 427 The peak-to-peak amplitude is calculated by multiplying the rms value with the crest factor (which is currently fixed to 14). The Amplitude p-p box shows how much of delay line capacity the setting consumes. Agilent J-BERT N4903B High-Performance Serial BERT...
Page 428 The filter settings graph shows the actual and the possible jitter spectrum. In addition the total sRJ amplitude as rms value is displayed in UI and in ps. It is calculated using following formula: Agilent J-BERT N4903B High-Performance Serial BERT...
Page 429 When you enable the External Jitter the Jitter Setup function reserves the remaining free capacity of the 220ps delay line for the signal applied to the Delay Ctrl Input. The parameter window informs you about • Amplitude (max) • Voltage (max) • Slope Agilent J-BERT N4903B High-Performance Serial BERT...
Page 430 The Delay Control Input has an overvoltage protection. For details see “Delay Control N O T E Input - Concepts” on page 155. Slope The Slope indicates the present relation between the voltage applied and the resulting delay. Agilent J-BERT N4903B High-Performance Serial BERT...
Page 431: Interference Channel Setup
To set up the Interference Channel module, click Interference Channel from the Jitter submenu. To use the Interference Channel module: 1 Click the checkbox that enables the module. 2 Select a trace (refer to the technical specifications for details) 3 If desired, enable sinusoidal interference. Agilent J-BERT N4903B High-Performance Serial BERT...
Page 432: Interference Channel Setup - Reference
To enable the addition of sinusoidal interference, press the corresponding button. Set the parameters to desired values: Amplitude The peak-to-peak amplitude of sinusoidal interference must not exceed a certain level (see the technical specifications). Agilent J-BERT N4903B High-Performance Serial BERT...
Page 433: Jitter Tolerance Characterization
BER threshold is found. This is repeated for each subsequent jitter frequency step to provide a plot of the DUT tolerance. Agilent J-BERT N4903B High-Performance Serial BERT...
Page 434 Whether SJ or PJ is used depends on the jitter frequency. SJ supports wide amplitude variations up to some MHz. PJ supports narrow amplitude variations over a wide frequency range. The measurement switches automatically between the two sources. Agilent J-BERT N4903B High-Performance Serial BERT...
Page 435 For devices that need some time to recover from the situation, a relax time can be specified. This time takes effect each time the BER limit has been exceeded. The next BER measurement starts after this time has elapsed. Agilent J-BERT N4903B High-Performance Serial BERT...
Page 436 The maximum amplitude (indicated by the dotted blue line) is given by the capability of the instrument. Searching downwards is usually faster than searching upwards, because the measurement of a single point is finished as soon as the BER is found to be above the limit. Agilent J-BERT N4903B High-Performance Serial BERT...
Page 437 Extended binary search takes more time than binary search but leads to reproducible results for devices with hysteresis. Agilent J-BERT N4903B High-Performance Serial BERT...
Page 438: Jitter Tolerance Characterization - Procedures
Setting the Frequency Range Choose Auto or Manual mode. In Auto mode, the jitter frequencies are automatically calculated: 1 Enter the Start Frequency. 2 Enter the Stop Frequency. Start and stop frequency define the measurement's frequency range. Agilent J-BERT N4903B High-Performance Serial BERT...
Page 439 Setting a Confidence Level is generally recommended. See also “Target BER” on page 435. If you enable Absolute Bits/Errors, the measurement proceeds with the next amplitude as soon as one of the two numbers is reached. Agilent J-BERT N4903B High-Performance Serial BERT...
Page 440 3 Check the Minimum Jitter Curve and Maximum Jitter Curve checkboxs. For details see “Minimum and Maximum Jitter Curve” on page 446. 4 Press the respective Load... buttons to load your own defined minimum and maximum jitter curve, stored in a text file. Agilent J-BERT N4903B High-Performance Serial BERT...
Page 441 Running the Test Once you have specified the Frequency, BER, and Search criteria, press the Start button to run the test. The bar in the lower right-hand corner of the screen shows the progress. Agilent J-BERT N4903B High-Performance Serial BERT...
Page 442 The measurement results can be saved as HTML file. To generate the HTML report: 1 Click Jitter menu from list of menu option provided on the drop down menu. The following submenu will appear. Agilent J-BERT N4903B High-Performance Serial BERT...
Page 443: Jitter Tolerance Characterization - Reference
Number of Steps: The Number of Steps between start and stop defines the test frequencies. To determine the individual test frequencies, an algorithm divides the horizontal logarithmic scale into a set of logarithmically equidistant frequencies. Agilent J-BERT N4903B High-Performance Serial BERT...
Page 444 BER. It allows the DUT to recover from the situation. The unit is seconds. The next measurement starts after that time. Search Specification On this page of the Jitter Tolerance Properties dialog, you specify how the measurement proceeds upwards or downwards from one measured point to the Agilent J-BERT N4903B High-Performance Serial BERT...
Page 445 The test for one frequency stops when the BER limit is crossed or the maximum amplitude (which depends on the jitter frequency) is reached. For binary search, you can set the accuracy. Binary search Agilent J-BERT N4903B High-Performance Serial BERT...
Page 446: Jitter Tolerance Compliance
“HTML Report” on page 466 HTML Report Jitter Tolerance Compliance Jitter Tolerance Compliance - Concepts The Jitter Tolerance Compliance test is used to ensure that the jitter tolerance of the device under test complies with a certain standard. Agilent J-BERT N4903B High-Performance Serial BERT...
Page 447 Unit Intervals – UI) and a BER threshold which must not be exceeded. A simple example is shown in the figure below: Jitter Tolerance Curves Some standards are more detailed, as illustrated in the following figure: Agilent J-BERT N4903B High-Performance Serial BERT...
Page 448 The measurement results for each point can also be exported as a numerical list in text format. The maximum jitter amplitude the Serial BERT can generate is also frequency Instrument Capability dependent, as illustrated below. Agilent J-BERT N4903B High-Performance Serial BERT...
Page 449 When the measurement has finished, the jitter composition shown in the Jitter Setup window is restored. Target BER The target bit error ratio must be specified. The condition for moving from one jitter amplitude step to the next can be set to Agilent J-BERT N4903B High-Performance Serial BERT...
Page 450 In terms of the Serial BERT, a standard is represented by a sequence of paired numbers. Each pair consists of a frequency value (Hz) and the associated jitter amplitude value (UI). Also part of a standard specification are the standard’s name and descriptive text. Agilent J-BERT N4903B High-Performance Serial BERT...
Page 451 If a standard specifies a tolerance curve that is bit rate dependent, the curve is automatically adapted to the present bit rate. If you change the bit rate, the curve is automatically recalculated. The standards provided by Agilent cannot be edited locally. Agilent J-BERT N4903B High-Performance Serial BERT...
Page 452 You can freely specify the jitter frequency range and the number of points to be measured. You can also adjust the frequency range and the point positions to the loaded standard. In addition, you can add a margin to the standard. Agilent J-BERT N4903B High-Performance Serial BERT...
Page 453 The margin is set in percent. A margin of 25%, for example, has the effect that each amplitude value is multiplied by 1.25. The following figure shows an example of a measurement with a margin of 50% and sample point adaptation. Agilent J-BERT N4903B High-Performance Serial BERT...
Page 454: Jitter Tolerance Compliance - Procedures
Select either a predefined standard or load a standard from a text file. 1 Switch to the Standard tab. A preview and a short description of the selected standard are displayed. 2 To load a different standard, open the list. Agilent J-BERT N4903B High-Performance Serial BERT...
Page 455 Press Apply to Predefined Standards to load the data and add the standard to the list of predefined standards. For details see “Adding a User-Defined Standard” on page 461. If you wish to increase the stress on the device under test, you can enter a Margin. Agilent J-BERT N4903B High-Performance Serial BERT...
Page 456 When you change the selection state of the Auto Frequencies checkbox, press N O T E Apply on the Standard tab to accept the change and to update the frequency list. Agilent J-BERT N4903B High-Performance Serial BERT...
Page 457 It will be enabled only if the sequence is send to the PG. Setting the BER Limit 1 Set the Target Bit Error Ratio. This defines whether a measured point is flagged green (test passed) or red (test failed). Agilent J-BERT N4903B High-Performance Serial BERT...
Page 458 To avoid clock loss, the sinusoidal jitter component has to be enabled. Since the sinusoidal jitter for the test is generated internally, the jitter amplitude must be set to zero: 1 Press Jitter Setup from the Jitter submenu. Agilent J-BERT N4903B High-Performance Serial BERT...
Page 459 When the measurement is either completed or aborted, you can obtain a list of measured points by clicking the following tab which appears once the measurement is stopped. Clicking on the above tab you get the list of measured points. Agilent J-BERT N4903B High-Performance Serial BERT...
Page 460 1 Click on the >> icon on the Jitter menu. The following submenu will appear. 2 Select 'Generate HTML report'. 3 Select the folder where you want to save the report, name the file, and save it. Agilent J-BERT N4903B High-Performance Serial BERT...
Page 461 To save a measurement as an .jcp file for later use in the user interface: 1 After your measurement has finished and the results are displayed, select Save Measurement from the File > Save menu. 2 Select a proper file name and location and press the Save button. Agilent J-BERT N4903B High-Performance Serial BERT...
Page 462: Jitter Tolerance Compliance - Reference
BER at defined jitter levels. The jitter levels can be derived from predefined standards. Standard Specification The drop-down list contains all predefined standards, including user-defined Standard Selection standards. The shape of the selected standard is shown in the preview area. The Agilent J-BERT N4903B High-Performance Serial BERT...
Page 463 Level from Standard is only met if the trace to simulate the ISI is selected as in the description item Additional Jitter. Other settings of the ISI can change the DUT's input level up to four times. Agilent J-BERT N4903B High-Performance Serial BERT...
Page 464 – Checkbox is not selected: The list of frequencies yields a set of logarithmically equidistant frequencies. Alternatively, you can set the Number of Steps on the Standard tab. N O T E Agilent J-BERT N4903B High-Performance Serial BERT...
Page 465 The next BER measurement starts after this time has elapsed. To run the Jitter measurements you need to make sure that Global Jitter, Sinusoidal Optimal Measurement Setup Jitter and Periodic Jitter are enabled. Agilent J-BERT N4903B High-Performance Serial BERT...
Page 466 If you want to use the measurement results with other applications, you can export the data to a file via Analysis > Export Data..The contents of the resulting file may look as follows: Agilent J-BERT N4903B High-Performance Serial BERT...
Page 467 This file can be imported into spreadsheet applications such as Microsoft Excel, for example. Use the semicolons as delimiters for the rows or columns. The comment can be entered with the Modify Comment button below the graphical T I P result view. Agilent J-BERT N4903B High-Performance Serial BERT...
Page 468 Jitter Tolerance Tests Agilent J-BERT N4903B High-Performance Serial BERT...
Page 469: Solving Problems
Agilent J-BERT N4903B High-Performance Serial BERT User Guide Solving Problems Solving Problems - Concepts This section provides information that can help you to troubleshoot the Serial BERT in case any problems occur. Setup Problems Setup Problems - Concepts You may run into the following problems when setting up the Serial BERT.
Page 470 This indicator turns red when no clock signal is detected at the ED Clock In port. BERT connected looped back or to your device: • The PG clock output is off or not connected. • There is no connection to the ED clock input. • Your cables are faulty. Agilent J-BERT N4903B High-Performance Serial BERT...
Page 471 Your device has changed the data pattern. Set the ED and PG patterns separately. • If the fundamental BER of your device is higher than the sync threshold BER, you can select a higher sync threshold BER. Agilent J-BERT N4903B High-Performance Serial BERT...
Page 472: Measurement Problems
Accumulated measurements can help you determine the cause of bit errors. Bit errors can be caused by a variety of problems. In addition, instrument settings can affect how errors are measured and displayed. The sync mode setting has the greatest effect. Agilent J-BERT N4903B High-Performance Serial BERT...
Page 473 BER. The accumulated results table displays the total accumulated error ratio. Look in N O T E the measurement log file to see the error ratio during the period of constant errors. Agilent J-BERT N4903B High-Performance Serial BERT...
Page 474 The noise may originate somewhere else within your device or system, causing random bit errors to be passed on to other components. Therefore, your device may have a good output waveform and still transmit random bit errors. Agilent J-BERT N4903B High-Performance Serial BERT...
Page 475 Data in this measurement log file confirms that there were periods of momentary Example Log of Sync and Clock Loss clock loss. Agilent J-BERT N4903B High-Performance Serial BERT...
Page 476 Your log file may be missing up to the last ten seconds of data. To avoid this condition, accumulate for 10 seconds longer than desired. You can view and analyze the following information in the measurement log file: Agilent J-BERT N4903B High-Performance Serial BERT...
Page 477 ERROR FREE SECONDS Cumulative ED CLOCK LOSS ERROR DECISECONDS Cumulative DATA LOSS ERROR FREE DECISECONDS Cumulative SYNC LOSS SECONDS Cumulative BURST STATUS Cumulative BURST SYNC RATIO Cumulative TOTAL BURST COUNT Cumulative BAD BURST COUNT Cumulative Agilent J-BERT N4903B High-Performance Serial BERT...
Page 478: Other Messages
BERT and let it cool down before operating it again. If the Serial BERT is operated at this state for a longer time, the temperature may Critical Temperature reach a critical level. In this case, the following message is displayed: Agilent J-BERT N4903B High-Performance Serial BERT...
Page 479 When you are switching on the Serial BERT after it was shut down due to a temperature error, you will see a message box that informs you about which module caused the problem. Agilent J-BERT N4903B High-Performance Serial BERT...
Page 480: N4916B System Setup Calibration
3 Use the drop down list to provide the Input Timing Setup. 4 Click Load Calibration Settings to continue. A message will pop up which warns you to save the instrument settings before continuing the calibration. Agilent J-BERT N4903B High-Performance Serial BERT...
Page 481 – Connect Clock Out of Pattern Generator with Clock In of Error Detector. – Terminate Clock Out of Pattern Generator with 50 Ohm termination resistor – For each of the 6 timing settings do a BER measurement using the following accumulation setting Agilent J-BERT N4903B High-Performance Serial BERT...
Page 482 Example: Input Timing Setting 2 has the biggest ‘distance’ to a setting that produced errors, no matter if checking in ‘forward’ or ‘backward’ direction through the table. So this is the setting that has to be used. Agilent J-BERT N4903B High-Performance Serial BERT...
Page 483 – Selection of the optimum Input Timing setting is done as shown above for the BER measurement. 4 Selection of the optimum Input Timing setting is done as shown above for the BER measurement. 5 Optionally reload the previously stored instrument state Agilent J-BERT N4903B High-Performance Serial BERT...
Page 484 1 N4903B with option D14 2 N4916B specified for up to 14.2Gb/s 3 Infiniium DCA 86100A with a 83484A module • Connect the N4916B with the N4903B using the N4915A-010 matched cable Setup Description pair Agilent J-BERT N4903B High-Performance Serial BERT...
Page 485 When all 6 settings have been measured, select the optimum input timing setting (keep in mind that one erroneous sample on the screen has to be treated as an error). Example screen shots • Input Timing Setup = 1 Agilent J-BERT N4903B High-Performance Serial BERT...
Page 486 Solving Problems • Input Timing Setup = 2 • Input Timing Setup = 3 Agilent J-BERT N4903B High-Performance Serial BERT...
Page 487 Solving Problems • Input Timing Setup = 4 • Input Timing Setup = 5 Agilent J-BERT N4903B High-Performance Serial BERT...
Page 488 Solving Problems • Input Timing Setup = 6 Input Timing Setup #1 shows timing violations at the input of the N4916B. All other measurements do not show any violations during the measurement interval (6 minutes). Agilent J-BERT N4903B High-Performance Serial BERT...
Page 489 In the example above the following values have been used: • #bits = 4 • Target BER = 10 • Data Rate = 14.2 Gb/s This gives a time base setting of 28.2ps and a measurement time of 338 seconds. Agilent J-BERT N4903B High-Performance Serial BERT...
Page 490: N4876A System Setup Adjustment
2 Select the external instrument from the given list. For example, here you will select N4876A. 3 Click Adjustment... to continue. A message will pop up which warns you to save the instrument settings before continuing the auto adjustment process. Agilent J-BERT N4903B High-Performance Serial BERT...
Page 491 The adjustment process may take several minutes for completion. N O T E The following message will pop up after the successful completion of adjustment process. Agilent J-BERT N4903B High-Performance Serial BERT...
Page 492: M8061A System Setup Adjustment
A message will pop up which warns you to save the instrument settings before continuing the auto adjustment process. 4 Click Yes to continue if you have already saved the settings. Once the auto adjustment starts, you will see the adjustment progress in the following screen: Agilent J-BERT N4903B High-Performance Serial BERT...
Page 493: Problems With The N4916A
When you have opened the External Instrument(s) - Config window and have selected N4916A from the external instruments, select De-emphasis under Enable Function column in the list, the N4916A Connection window appears. Cannot-Connect Problems An error message may appear when you now press Enable. Agilent J-BERT N4903B High-Performance Serial BERT...
Page 494 3 From the Agilent IO Control menu, open the VISA Assistant. 4 If no VISA alias name has been assigned so far, the VISA Assistant should indicate an instrument named "UsbDevice1". If the N4916A has been installed Agilent J-BERT N4903B High-Performance Serial BERT...
Page 495 6 In the Instr. Lang. box (Instrument Language), enable SCPI. 7 Click the *IDN? button. This generates the identification query in SCPI format. The instrument should return "Agilent Technologies, N4916A,," and the software revision. If you could proceed until here, the N4916A power supply and the processor are fully functional.
Page 496 1 Set the Data offset to 0 V and the amplitude to 1 V. Set the De-Emphasis to 6 2 Connect the Output of the N4916A to an oscilloscope. 3 Connect the trigger output of the Serial BERT to the trigger input of the oscilloscope. Agilent J-BERT N4903B High-Performance Serial BERT...
Page 497 – Press the Edit button to enter the ED Input Setup Dialog. – Set the Input to "Normal". – Set the Input Range to –1 V to +1 V. – Set the Threshold to "Averaging". – Set the Termination to 0 V. Agilent J-BERT N4903B High-Performance Serial BERT...
Page 498 5 Ensure that the error detector follows the generated pattern. – Press the Auto Align button. – From the Analysis panel select the Eye Diagram page. – Press the Start button. The eye diagram should look like this after some seconds: Agilent J-BERT N4903B High-Performance Serial BERT...
Page 499 1 Set up the pattern generator as described above: Set the Data Offset to 0 V and the Amplitude to 1 V. 2 Set up the error detector as described above. Agilent J-BERT N4903B High-Performance Serial BERT...
Page 500: Problems With The N4916B
Problems with the N4916B - Concepts When you have opened the External Instrument(s) - Config window and have selected N4916B from the external instruments, select De-emphasis under Enable Function column in the list, the N4916B Connection window appears. Agilent J-BERT N4903B High-Performance Serial BERT...
Page 501 N4916B and one of the USB ports at the rear of the Serial BERT. 1 Open the Utility menu and click Minimize GUI to gain access to the Windows operating system. 2 In the Windows task bar, click the Agilent IO Control icon. Agilent J-BERT N4903B High-Performance Serial BERT...
Page 502 "UsbInstrument1". If the N4916B has been installed correctly, the VISA Assistant should indicate an instrument named "DATA_OUT". Click UsbInstrument1 or DATA_OUT. 5 Click the Formatted I/O tab. 6 In the Instr. Lang. box (Instrument Language), enable SCPI. Agilent J-BERT N4903B High-Performance Serial BERT...
Page 503 Solving Problems 7 Click the *IDN? button. This generates the identification query in SCPI format. The instrument should return "Agilent Technologies, N4916B,," and the software revision. If you could proceed until here, the N4916B power supply and the processor are fully functional.
Page 504 1 Connect the scope Data out of N4916B 2 Connect the Trigger In of Scope to Trigger Out of PG 3 Terminate N4916B Data /Out with 50Ohm 4 Terminate PG Trigger/Out with 50Ohm 5 Terminate PG Data/Out with 50Ohm Agilent J-BERT N4903B High-Performance Serial BERT...
Page 505 4 Terminate PG Clock Out with 50Ohm 5 Ensure that the error detector follows the generated pattern. – Press the Auto Align button. – From the Analysis panel select the Eye Diagram page. – Press the Start button. Agilent J-BERT N4903B High-Performance Serial BERT...
Page 506 As long as the N4916B is in "connected" state (after pressing the Enable button), N O T E the pattern generator's output is programmed to a fixed level. The amplitude is set to 1.2 V, the offset to 0. This yields a signal of ±0.6 V. Agilent J-BERT N4903B High-Performance Serial BERT...
Page 507 Input Frequency 3GHz • Termination ON at 0V Check the Output of the N4916B (Clock Multiplier Part) Using a Scope ( Clock Multiplier 1) Following are the steps to test clock multiplier 1 using a scope: Agilent J-BERT N4903B High-Performance Serial BERT...
Page 508 3 Termiate PG Trigger Out with 50 Ohm 4 Terminate Clock Multiplier Clock In with 50 Ohm 5 Set Clock Multipiler to 1 6 Measure the signal on scope. It will show an output like the following: Agilent J-BERT N4903B High-Performance Serial BERT...
Page 509 3 Termiate PG Trigger Out with 50 Ohm 4 Terminate Clock Multiplier Clock In with 50 Ohm 5 Set Clock Multipiler to 2 6 Measure the signal on scope. It will show an output like the following: Agilent J-BERT N4903B High-Performance Serial BERT...
Page 510 Constantly green when LAN is operable Constantly red when LAN is not operable Flashing green when device identification is enabled POWER Constantly red when instrument is OFF (in power standby mode) Constantly green when instrument is ON (powered) Agilent J-BERT N4903B High-Performance Serial BERT...
Page 511: Problems With The N4876A
N4876A and one of the USB ports at the rear of the Serial BERT. 1 Open the Utility menu and click Minimize GUI to gain access to the Windows operating system. 2 In the Windows task bar, click the Agilent IO Control icon. Agilent J-BERT N4903B High-Performance Serial BERT...
Page 512 "UsbInstrument1". If the N4876A has been installed correctly, the VISA Assistant should indicate an instrument named "N4876A". Click UsbInstrument1 or N4876A. 5 Click the Formatted I/O tab. 6 In the Instr. Lang. box (Instrument Language), enable SCPI. Agilent J-BERT N4903B High-Performance Serial BERT...
Page 513 Solving Problems 7 Click the *IDN? button. This generates the identification query in SCPI format. The instrument should return "Agilent Technologies, N4876A," and the software revision. If you could proceed until here, the N4876A power supply and the processor are fully functional.
Page 514 2 Connect the Trigger-In of Scope to Trigger-Out of PG 3 Terminate N4876A Data /Out with 50 Ohm 4 Terminate PG Trigger-/Out with 50 Ohm 5 Terminate PG Data /Out and Aux /Data Out with 50 Ohm Agilent J-BERT N4903B High-Performance Serial BERT...
Page 515 If you have connected the N4876A to a Serial BERT and have no oscilloscope at hand, you can use the error detector for checking the output of the N4876A. 1 Connect the ED Data-In to the Data-Out of N4876A 2 Connect the ED CLK-In to the PG-CLK Out Agilent J-BERT N4903B High-Performance Serial BERT...
Page 516 The amplitude is set to 0.8 V, the offset to -0.4 V. The oscilloscope should show the following picture for Data Out as well as for Aux Data Out: Agilent J-BERT N4903B High-Performance Serial BERT...
Page 517 Flashing orange when an overload condition has been detected Constantly orange during boot phase of the instrument Activity Flashes green when instrument is accessed on the remote interfaces Constantly orange during boot phase of the instrument Agilent J-BERT N4903B High-Performance Serial BERT...
Page 518: Problems With The M8061A
Ensure that the power cord is connected. Check for the steady green "STATUS" light that appears on the ESM of the chassis indicating a power ready status of the chassis which mounts the M8061A module. Check for the status LEDs present Agilent J-BERT N4903B High-Performance Serial BERT...
Page 519 Ensure that the USB cable is properly connected between the USB ports of the M8061A and one of the USB ports of the J-BERT N4903B. Use the matched USB cable to establish the USB connection. The mini USB port is available at the front side of the AXI frame which is mounting the M8061A module.
Page 520 M8061A Connection dialog. 6 Click Enable button. It enables M8061A Multiplexer with Deemphasis that is connected between data out of J-BERT N4903B and the DUT. Once the Mux with Deemphasis function is enabled, you will see the Mux with Deemphasis parameters in the M8061A window.
Page 521 4 Terminate PG Trigger-/Out with 50 Ohm. 5 Terminate PG Data /Out and Aux /Data Out with 50 Ohm. Then the oscilloscope should show an output eye like the following: If you see a display like above everything is OK. Agilent J-BERT N4903B High-Performance Serial BERT...
Page 522 Aux Clk Out, it should give a clock signal of set set data rate with an offset of 0V and an amplitude of 700 mV. if one of the used J-BERT N4903B outputs is not providing the expected signal, then the J-BERT N4903B is defective.
Page 523 After the M8061A is ready, the red "FAIL" LED goes off and the green "ACCESS" LED stays on. • When the green "ACCESS" LED is on, you can start the firmware. • When the firmware is communicating successfully with the module, the green "ACCESS" LED starts flashing. Agilent J-BERT N4903B High-Performance Serial BERT...
Page 524 Solving Problems Agilent J-BERT N4903B High-Performance Serial BERT...
Page 525: Customizing The Instrument
Agilent J-BERT N4903B High-Performance Serial BERT User Guide Customizing the Instrument Customizing the Instrument - Concepts The Serial BERT provides various utilities for adjusting the instrument to your personal preferences. Restoring the System Agilent Recovery System - Procedures The Agilent Recovery System can be used to repair the system in case of serious malfunction.
Page 526 2 From the boot screen, select Agilent Recovery System boot option. This screen will be shown only for few seconds. N O T E You will be now able to see the Agilent Recovery System user interface. This user interface provides the following options: Agilent J-BERT N4903B High-Performance Serial BERT...
Page 527 The Agilent Recovery System will now restore the factory settings. You must not turn off the instrument or remove the power before the process completes. Doing so may result in system corruption and the application may not operate. Agilent J-BERT N4903B High-Performance Serial BERT...
Page 528: Configuring The Instrument
Do not interrupt the BIOS update. Note that you must reboot the instrument after updating the firmware. If you do not reboot the instrument, the firmware may not have access to the instrument's hardware. Agilent J-BERT N4903B High-Performance Serial BERT...
Page 529: Configuring The Instrument - Procedures
You can connect an external monitor, mouse and keyboard to the instrument on the Serial BERT's rear panel. To connect a mouse or a keyboard, you can use either the USB ports or the PS/2 ports. Agilent J-BERT N4903B High-Performance Serial BERT...
Page 530 Installing or overwriting files on the Serial BERT computer system may impact the operation of the instrument. Please contact your network administrator or IT department to find out whether you have this type of network. Agilent J-BERT N4903B High-Performance Serial BERT...
Page 531: Configuring The Instrument - Reference
Configuring the Touchscreen Configuring the Touchscreen - Procedures The following procedures help you to configure the touchscreen according to your personal needs: Turning the Touchscreen Off/On This function disables the instrument touchscreen, external keyboard, and mouse. Agilent J-BERT N4903B High-Performance Serial BERT...
Page 532 You can use the on-screen keyboard to enter text in any text field. It can be used along with the standard keyboard or keypad. 1 Click in a text field to position the cursor in it. Agilent J-BERT N4903B High-Performance Serial BERT...
Page 533: Configuring The Touchscreen - Reference
This section describes the options of the on-screen keyboard: Click Set to access the Options menu: • Move OSK Window Click this to enable the arrow keys on your actual keyboard. They can then move the software keyboard. Agilent J-BERT N4903B High-Performance Serial BERT...
Page 534 T I P Block Full, the keyboard may cover most of the instrument display. If this occurs, continue to make your keyboard entry, then either close the on screen keyboard or change to a smaller display. Agilent J-BERT N4903B High-Performance Serial BERT...
Page 535: Installing Software Licenses
2 In the Utilities menu, click Licenses. 3 Double-click the feature you wish to enable. 4 Follow the instructions in the window. Installing Software Licenses - Reference This section explains the options for installing a license. Agilent J-BERT N4903B High-Performance Serial BERT...
Page 536: Installing Hardware Options
That means, you need to read (and probably print) the license file with a text editor and type the key code. Installing Hardware Options Installing Hardware Options - Procedures The Serial BERT has a slot for installing optional hardware. Agilent J-BERT N4903B High-Performance Serial BERT...
Page 537 “Interference Channel” on page If you connect P1 to the Data Out of the Pattern Generator, P2 provides the output that is meant to be connected to the DUT. This is ilustrated in the following figure. Agilent J-BERT N4903B High-Performance Serial BERT...
Page 538: Installing External Instrument(S)
To install N4876A 28Gb/s Multiplexer with Serial BERT, see “Installing the N4876A - Procedure” on page 544 • M8061A 28 Gb/s Multiplexer with De-emphasis To install M8061A with J-BERT N4903B, see “Installing the M8061A - Procedure” on page 549 Agilent J-BERT N4903B High-Performance Serial BERT...
Page 539: Installing The N4916A/B - Procedure
1 In the Utility menu, click Minimize GUI to access the Windows operating system. 2 Click the Agilent IO Control icon in the Windows task bar to open the IO Control menu. You will see the menu item Agilent Connection Expert in the Windows task bar. Agilent J-BERT N4903B High-Performance Serial BERT...
Page 540 B and the Serial BERT. You can use any rear port of the Serial BERT. 3 The Found New Hardware Wizard will pop up and ask whether he should connect to Windows Update. 4 Click No, not this time. Agilent J-BERT N4903B High-Performance Serial BERT...
Page 541 5 Click Next and let the Wizard locate the appropriate driver. The USB driver is part of the Agilent IO Libraries Suite. 6 Step through the Wizard by clicking Next. The Wizard will finally set up a USB device named "USB Test and Measurement Device". Agilent J-BERT N4903B High-Performance Serial BERT...
Page 542 "D4916" is the alias used by the software. For N4916B, change the alias name to DATA_OUT/AUXDATA_OUT depending on the channel (Data Out and Aux Data Out) used. "DATA_OUT"/"AUXDATA_OUT" is the alias used by the software. Agilent J-BERT N4903B High-Performance Serial BERT...
Page 543 For detailed instructions refer to the Connectivity Guide which is part of the Agilent IO Libraries Suite Documentation. Connecting to Pattern Generator and DUT (N4916A) After the USB port has been configured, you can remove keyboard and mouse and make the signal connections. Agilent J-BERT N4903B High-Performance Serial BERT...
Page 544: Installing The N4876A - Procedure
For this configuration, you may wish to connect a keyboard and a mouse to the Serial BERT (see “Connecting Peripherals” on page 529). This is not mandatory but convenient – the keys provided by the instrument can be used as well for Agilent J-BERT N4903B High-Performance Serial BERT...
Page 545 2 Click the Agilent IO Control icon in the Windows task bar to open the IO Control menu. You see the menu item Agilent Connection Expert in the Windows task bar. 3 Click the About item to check the details. Agilent J-BERT N4903B High-Performance Serial BERT...
Page 546 5 Click Next and let the Wizard locate the appropriate driver. The USB driver is part of the Agilent IO Libraries Suite. 6 Step through the Wizard by clicking Next. The Wizard will finally set up a USB device named "USB Test and Measurement Device". Agilent J-BERT N4903B High-Performance Serial BERT...
Page 547 2 In the Instrument I/O panel, For N4876A, click UsbInstrument1. "UsbInstrument1" is the default alias name for N4876A. 3 Click Change Properties and change the alias name. For N4876A, change the alias name to "N4876A". Agilent J-BERT N4903B High-Performance Serial BERT...
Page 548 After the USB port has been configured, you can remove keyboard and mouse and make the signal connections. 1 Disable the outputs of N4903B and use the matched cable kit (2x 2.4 mm to SMA for data, 1x SMA-to-SMA for clock) with the part number N4915A-001 to Agilent J-BERT N4903B High-Performance Serial BERT...
Page 549: Installing The M8061A - Procedure
528). Connecting the M8061A with J-BERT N4903B via USB The M8061A is controlled by the J-BERT N4903B via USB. Use the matched USB cable assembly (USB 28-AWG 2.0 standard male A to B mini 4-conductor 3-mm) to establish the USB connection. The mini USB port is available at the front side of the AXI frame which is mounting the M8061A module.
Page 550 Agilent recommends you to establish a USB connection between the USB ports of N O T E M8061A and J-BERT N4903B via a powered USB 2.0 hub to prevent the USB port shutdown due to excessive power drawn by the USB devices connected at the J- BERT N4903B USB ports.
Page 551: Installing Webserver
J-BERT provides the option of web server, and installing this program enables users to access the instrument remotely over LAN. The four basic steps to using a web browser: 1 Open the web browser and enter the URL for the target instrument Agilent J-BERT N4903B High-Performance Serial BERT...
Page 552 2 Unzip the folder, because the installation can only be started from an unzipped folder. Install the Web Server software. Follow the instructions prompted by the installation process. 3 Launch N4903 software. Click on Utility menu item. The following submenu will appear. Agilent J-BERT N4903B High-Performance Serial BERT...
Page 553 Additionally the WebServer running on the instrument can be enabled/disabled, and a password can be specified. Without a valid password you can not access the instrument's GUI. The following screen displays the WebControl dialog. Agilent J-BERT N4903B High-Performance Serial BERT...
Page 554 1 Open a web browser, either Internet Explorer 4.0 or higher, or Netscape 4.0 or higher. 2 Type in the instrument IP, and enter the password when it prompts for it. 3 From this page you can access all the functionalities of the J-BERT. Agilent J-BERT N4903B High-Performance Serial BERT...
Page 555: Printing
The instrument will then prompt you to locate the drive for printer driver. Type the path where the printer driver is copied. 5 Follow all other instructions on the screen to finish adding a printer. Agilent J-BERT N4903B High-Performance Serial BERT...
Page 556 To print a hardcopy of the instrument's display to the default printer: • Click Print from the File menu on the main menu bar. Agilent J-BERT N4903B High-Performance Serial BERT...
Page 557 2 Check if the printer driver for your printer is installed. 3 Check if the printer port is configured correctly. For more information on printer problems, see the printer's operation manual. Agilent J-BERT N4903B High-Performance Serial BERT...
Page 558 To save the setup with a new filename or directory path, do the following: • In the File menu, click Save and then Save Instrument State As..This opens a dialog box, which allows you to create subdirectories, rename setup files, or overwrite existing setup files. Agilent J-BERT N4903B High-Performance Serial BERT...
Page 559 1 Copy the measurement log file from the Serial BERT to your PC. By default, log files are saved in the folder C:\<instrument model>\log. Agilent J-BERT N4903B High-Performance Serial BERT...
Page 560 ERRORED 0 COUNT Cumulative ERRORED 0 RATIO ERRORED 0 RATIO Cumulative ERRORED 1 COUNT ERRORED 1 COUNT Cumulative ERRORED 1 RATIO ERRORED 1 RATIO Cumulative SYNC LOSS ERROR SECONDS Cumulative PG CLOCK LOSS ERROR FREE SECONDS Cumulative Agilent J-BERT N4903B High-Performance Serial BERT...
Page 561 The instrument allows you to save an image of the current display screen. You can save this image to the internal hard disk or a USB stick. You can later print this file or import it to a word processing or graphics editing program. Agilent J-BERT N4903B High-Performance Serial BERT...
Page 562 To reset the instrument to the preset state select one of the following options: • Press the Preset button on the front panel. • Select Preset in the File menu. • Send an *RST command to the GPIB controller. Agilent J-BERT N4903B High-Performance Serial BERT...
Page 563 Self Test - Procedures Running Self Test To run a self test: 1 Select Self Test from the Utility menu. Agilent J-BERT N4903B High-Performance Serial BERT...
Page 564 • Error Detector Auto Calibration This test runs a timing calibration that calibrates the clock to data alignment of the error detector. It may take about 45 minutes to complete. Agilent J-BERT N4903B High-Performance Serial BERT...
Page 565 After the self test has finished, the results (Success or Failed) are displayed next to each test. If a test has failed, you can use the Message button to open the BIOS Messages window with detailed error messages explaining the failure reason. Agilent J-BERT N4903B High-Performance Serial BERT...
Page 566 Customizing the Instrument Agilent J-BERT N4903B High-Performance Serial BERT...
Page 567 MUX/DEMUX Pair, 32 Error Detector, 205 BUJ, 398 N4876A, 34 Auxiliary Out port, 170 Burst Results, 383 N4916A, 34 Auxiliary Output, 203 Burst Sync Mode, 211 Oscilloscope, 32 Average 0/1 Threshold, 201 SONET/SDH Receiver, 33 Agilent J-BERT N4903B High-Performance Serial BERT...
Page 568 Eye Opening, 300 Disparity Error Ratio, 182 Changing Properties, 269 Output Levels, 276 Double Click Configuration, 532 Improving the Display, 268 Output Timing, 258 DUT Connecting, 29 Running the measurement, 266 Spectral Jitter, 358 Agilent J-BERT N4903B High-Performance Serial BERT...
Page 569 Manual Pattern Alternation, 163 Fast Eye Mask, 312 Jitter Setup Area, 415 Manually Inserting Errors, 157 Output Levels, 271 Jitter Tolerance Mark Density, 92 Output Timing, 253 Reference, 443 Number of Top Frequencies to Show, Agilent J-BERT N4903B High-Performance Serial BERT...
Page 570 Eye Opening, 295 Q Factor, 280 Fast Eye Mask, 312 Q High Level, 280 Output Levels, 270 Q High Level Nr. Points, 281 Output Timing, 252 Q High Level R^2, 281 Spectral Jitter, 353 Agilent J-BERT N4903B High-Performance Serial BERT...
Page 571 100 Eye Opening, 298 absolute, 312 Sequence Editor, 101 Output Levels, 274 offset, 312 Toolbox, 104 Output Timing, 256 percentage, 312 Sequence Mode, 98 Spectral Jitter, 357 Threshold Eye Opening, 301 SequenceExpression, 96 Agilent J-BERT N4903B High-Performance Serial BERT...
Page 572 Fast Eye Mask, 314 Vlo, 136 Zero SubstitutionPattern Vof, 135 zero substitution, 92 Voltage Zoom Function Xover, 137 of measurement point, 313 Eye Opening, 300 Output Level, 276 Output Timing, 259 Spectral Jitter, 359 Waveform, 320 Agilent J-BERT N4903B High-Performance Serial BERT...

Agilent Technologies J-BERT N4903B User Manual

1 Planning the Test

2 Setting up External Instrument(S)

3 Setting up Patterns

4 Setting up the Pattern Generator

5 Setting up the Error Detector

6 Advanced Analysis

7 Evaluating Results

8 Jitter Tolerance Tests

9 Solving Problems

10 Customizing the Instrument

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