Start; Stop; Data Pattern; Data Rate - Altera Cyclone IV GX User Manual

Chapter 6: Board Test System
Using the Board Test System
The following sections describe the controls on the PCIe tab.

Start

The Start control initiates the loopback tests.

Stop

The Stop control terminates the loopback tests.

Data Pattern

The Data pattern control specifies the type of data contained in the transactions. The
following data types are available for analysis:
PRBS 7—Selects pseudo-random 7-bit sequences.
■
■ PRBS 15—Selects pseudo-random 15-bit sequences.
■ PRBS 23—Selects pseudo-random 23-bit sequences.
■ PRBS 31—Selects pseudo-random 31-bit sequences.
■ PCIe compliance—Selects the repeating 40-bit PCIe compliance pattern:
/K28.5/D21.5/K28.5/D10.2/with the first /K28.5/ code group encoded with
negative current disparity (0011111010) to conform to the PCIe protocol. The
pattern is intended to be a signal loopback to demonstrate signal quality rather
than a complete PCIe compliance test.

Data Rate

The Data rate control specifies the speed of the transactions. The following data rates
are available for analysis:
■ 1.25 Gbps—Selects a 1.25 Gbps transaction data rate.
■ 2.5 Gbps—Selects a 2.5 Gbps transaction data rate.

Control Register Settings

The Control register settings controls specify loopback test parameters. The
following settings are available for analysis:
■ Serial loopback—Routes signals back to the sender.
■ VOD—Specifies the voltage output differential of the transmitter buffer.
Pre-emphasis—Specifies the amount of pre-emphasis on the transmitter buffer.
■
RX equalizer—Enables the static equalizer.
■
■ DC gain—Specifies the boost to incoming signals.

Status

These controls display current transaction performance analysis information collected
since you last clicked Start:
■ PLL lock—Shows the PLL locked or unlocked state.
■ Pattern sync—Shows the pattern synced or not synced state. The pattern is
considered synced when the start of the data sequence is detected.
© March 2010 Altera Corporation Cyclone IV GX Transceiver Starter Kit User Guide
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