at91sam9263 ATMEL Corporation, at91sam9263 Datasheet - Page 95

• Manufacturer Part Number: at91sam9263
• Description: At91 Arm Thumb Microcontrollers
• Manufacturer: ATMEL Corporation

13. AT91SAM9263 Boot Program
13.1
13.2
6249D–ATARM–20-Dec-07
Description
Flow Diagram
The Boot Program integrates different programs permitting download and/or upload into the dif-
ferent memories of the product.
First, it initializes the Debug Unit serial port (DBGU) and the USB Device Port.
Then the SD Card Boot program is executed. It looks for a boot.bin file in the root directory of a
FAT12/16/32 formatted SD Card. If such a file is found, code is downloaded into the internal
SRAM. This is followed by a remap and a jump to the first address of the SRAM.
If the SD Card is not formatted or if boot.bin file is not found, NANDFlash Boot program is then
executed. First, as for SD Card Boot part, it looks for a boot.bin file in the root directory of a
FAT12/16/32 formatted NANDFlash. If such a file is found, the code is downloaded into the inter-
nal SRAM. This is followed by a remap and a jump to the first address of the SRAM.
If the NANDFlash is not formatted, the NANDFlash Boot program looks for a sequence of seven
valid ARM exception vectors. If such a sequence is found, code is downloaded into the internal
SRAM. This is followed by a remap and a jump to the first address of the SRAM.
If no valid ARM vector sequence is found, the DataFlash
a sequence of seven valid ARM exception vectors in a DataFlash connected to the SPI. All
these vectors must be B-branch or LDR load register instructions except for the sixth vector.
This vector is used to store the size of the image to download.
If a valid sequence is found, code is downloaded into the internal SRAM. This is followed by a
remap and a jump to the first address of the SRAM.
If no boot.bin file is found, SAM-BA
USB device, or on the DBGU serial port.
The Boot Program implements the algorithm in
®
Boot is then executed. It waits for transactions either on the
AT91SAM9263 Preliminary
Figure
13-1.
®
Boot program is executed. It looks for
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