Atmel AT91 ARM Application Note
Thumb-based microcontroller
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Also See for AT91 ARM:
- Application note (12 pages) ,
- Application note (22 pages) ,
- Application note (8 pages)
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AT91SAM7SE Microcontroller Series Schematic
1. Introduction
This application note is a schematic review check list for systems embedding Atmel's
AT91SAM7SE series of ARM
It gives requirements concerning the different pin connections that must be consid-
ered before starting any new board design and describes the minimum hardware
resources required to quickly develop an application with the AT91SAM7SE Series. It
does not consider PCB layout constraints.
It also gives advice regarding low-power design constraints to minimize power
consumption.
This application note is not intended to be exhaustive. Its objective is to cover as
many configurations of use as possible.
The Check List table has a column reserved for reviewing designers to verify the line
item has been checked.
Check List
®
®
Thumb
-based microcontrollers.
AT91 ARM
Thumb-based
Microcontroller
Application Note
6261E–ATARM–18-Dec-07
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Summary of Contents for Atmel AT91 ARM
- Page 1 AT91SAM7SE Microcontroller Series Schematic Check List AT91 ARM 1. Introduction Thumb-based This application note is a schematic review check list for systems embedding Atmel’s ® ® AT91SAM7SE series of ARM Thumb -based microcontrollers. Microcontroller It gives requirements concerning the different pin connections that must be consid- ered before starting any new board design and describes the minimum hardware resources required to quickly develop an application with the AT91SAM7SE Series.
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Page 2: Associated Documentation
Before going further into this application note, it is strongly recommended to check the latest documents for the AT91SAM7SE Series Microcontrollers on Atmel’s Web site. Table 2-1 gives the associated documentation needed to support full understanding of this appli- cation note. -
Page 3: Schematic Check List
Application Note 3. Schematic Check List 3.3V Single Power Supply Strategy (On-chip Voltage Regulator Used) To reduce power consumption, voltage regulator can be put in standby mode. 100nF VDDFLASH 100nF VDDIO DC/DC Converter VDDIN 4.7µF 100nF 3.3V Voltage Regulator 2.2µF 100nF VDDOUT 100nF... - Page 4 Signal Name Recommended Pin Connection Description 1.65 to 1.95V VDDCORE Can be connected directly to VDDOUT pin Powers device and flash logic, on-chip RC. (1)(2) Decoupling capacitor (100 nF) 1.65 to 1.95V VDDPLL Can be connected directly to VDDOUT pin Powers the main oscillator and the PLL.
- Page 5 Application Note 3.3V and 1.8V Dual Power Supply Strategy (On-chip Voltage Regulator NOT Used and ADC Used) To reduce power consumption, voltage regulator can be put in standby mode. 100nF VDDFLASH 100nF VDDIO DC/DC Converter VDDIN 4.7µF 100nF 3.3V 2.2µF 100nF VDDOUT 100nF...
- Page 6 Signal Name Recommended Pin Connection Description Powers device logic, on-chip RC and Flash. 1.65 to 1.95V VDDCORE Decoupling/Filtering capacitors Decoupling/Filtering capacitors must be added to improve (1)(2) (100 nF and 2.2 µF) startup stability and reduce source voltage drop. 1.65 to 1.95V VDDPLL Powers the main oscillator and the PLL.
- Page 7 Application Note 3.3V and 1.8V Dual Power Supply Strategy (On-chip Voltage Regulator and ADC NOT Used) 100nF VDDFLASH DC/DC Converter VDDIO 4.7µF 100nF 3.3V VDDIN VDDOUT 100nF VDDPLL DC/DC Converter VDDCORE 2.2µF 100nF 1.8V 3.3V and 1.8V Dual Power Supply Schematic Example: On-chip voltage regulator is not used - ADC is not used - power supply on VDDIO: 3.3V Signal Name Recommended Pin Connection...
- Page 8 Signal Name Recommended Pin Connection Description Powers device logic, on-chip RC and Flash. 1.65 to 1.95V VDDCORE Decoupling/Filtering capacitors Decoupling/Filtering capacitors must be added to improve (1)(2) (100 nF and 2.2 µF) startup stability and reduce source voltage drop. 1.65 to 1.95V VDDPLL Powers the main oscillator and the PLL.
- Page 9 Application Note Signal Name Recommended Pin Connection Description Clock, Oscillator and PLL Internal Equivalent Load Capacitance (C For the AT91SAM7SE512/256: C = 20 pF For the AT91SAM7SE32: C = 11 pF Crystal Load Capacitance to check (C CRYSTAL AT91SAM7SE XOUT Crystals between 3 and 20 MHz XOUT Capacitors on XIN and XOUT...
- Page 10 Recommended Pin Connection Description See the Excel spreadsheet: “ATMEL_PLL_LFT_Filter_CALCULATOR_AT91_xxx.zip” (available in the software files on the Atmel Web site) allowing calculation of the best R-C1-C2 component values for the PLL Loop Back Filter. PLLRC Second-order filter PLLRC Can be left unconnected if PLL not used.
- Page 11 Application Note Signal Name Recommended Pin Connection Description ICE and JTAG Pull-up (100 kOhm) No internal pull-up resistor. Pull-up (100 kOhm) No internal pull-up resistor. Pull-up (100 kOhm) No internal pull-up resistor. Floating Output driven at up to V VDDIO In harsh environments , It is strongly Must be tied to V...
- Page 12 Signal Name Recommended Pin Connection Description All PIOs are pulled-up inputs at reset and are schmitt trigger inputs. PAx - PBx - PCx Application Dependant To reduce power consumption if not used, the concerned PIO can be configured as an output, driven at ‘0’ with internal pull-up disabled.
- Page 13 Application Note 5. See: Test Pin description in I/O Lines Considerations section of the AT91SAM7SE datasheet for more details on the different conditions to enter FFPI mode. 6. Example of USB Device connection: As there is an embedded pull-up, no external circuitry is necessary to enable and disable the 1.5 kOhm pull-up. To prevent over consumption when the host is disconnected, an external pull-down can be added to DDP and DDM.
- Page 14 4. External Bus Interface (EBI) Hardware Interface Table 4-1 details the connections to be applied between the EBI pins and the external devices for each Memory Controller: Table 4-1. EBI Pins and External Static Devices Connections Pins of the Interfaced Device 2 x 8-bit 16-bit 8-bit Static...
- Page 15 Application Note Table 4-1. EBI Pins and External Static Devices Connections (Continued) Pins of the Interfaced Device 2 x 8-bit 16-bit 8-bit Static CompactFlash NAND Static Static SDRAM CompactFlash Device True IDE Mode Flash Devices Device Controller SDRAMC SDCK – –...
- Page 16 5. AT91SAM Boot Program Hardware Constraints See AT91SAM Boot Program section of the AT91SAM7SE datasheet for more details on the boot program. SAM-BA Boot ™ The SAM-BA Boot Assistant supports serial communication via the DBGU or the USB Device Port: •...
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Page 17: Revision History
Application Note Revision History Change Request Doc. Rev Comments Ref. 6261A First issue Precision added to the pin descriptions of “TD0” “NRST” on page 6261B 3511 Added “External Bus Interface (EBI) Hardware Interface” on page Table 4-1, “EBI Pins and External Static Devices Connections,” on page 14, I/O[8:15] bits 6261C added in NAND Flash column. - Page 18 Disclaimer: The information in this document is provided in connection with Atmel products. No license, express or implied, by estoppel or otherwise, to any intellectual property right is granted by this document or in connection with the sale of Atmel products. EXCEPT AS SET FORTH IN ATMEL’S TERMS AND CONDI- TIONS OF SALE LOCATED ON ATMEL’S WEB SITE, ATMEL ASSUMES NO LIABILITY WHATSOEVER AND DISCLAIMS ANY EXPRESS, IMPLIED OR STATUTORY...