Datasheet

138
6120F–ATARM–03-Oct-06
AT91SAM7X512/256/128 Preliminary
21.5 Hardware and Software Constraints
• SAM-BA boot copies itself in the SRAM and uses a block of internal SRAM for variables and
stacks. The remaining available size for the user code is 122880 bytes forAT91SAM7x512,
57344 bytes for AT91SAM7X256 and 24576 bytes for AT91SAM7X128.
• USB requirements:
– pull-up on DDP
– 18.432 MHz Quartz
Table 21-4. User Area Addresses
Device Start Address End Address Size (bytes)
AT91SAM7X512 0x202000 0x220000 122880
AT91SAM7X256 0x202000 0x210000 57344
AT91SAM7X128 0x202000 0x208000 24576
Table 21-5. Pins Driven during Boot Program Execution
Peripheral Pin PIO Line
DBGU DRXD DRXD_PIO
DBGU DTXD DTXD_PIO