AT91SAM7S32-AI ATMEL [ATMEL Corporation], AT91SAM7S32-AI Datasheet - Page 83

• Manufacturer Part Number: AT91SAM7S32-AI
• Description: AT91 ARM Thumb-based Microcontrollers
• Manufacturer: ATMEL [ATMEL Corporation]

Internal Memory
Mapping
Internal Memory
Area 0
Remap Command
6071A–ATARM–28-Oct-04
Within the Internal Memory address space, the Address Decoder of the Memory Controller
decodes eight more address bits to allocate 1-Mbyte address spaces for the embedded
memories.
The allocated memories are accessed all along the 1-Mbyte address space and so are
repeated n times within this address space, n equaling 1M bytes divided by the size of the
memory.
When the address of the access is undefined within the internal memory area, the Address
Decoder returns an Abort to the master.
Figure 30. Internal Memory Mapping
The first 32 bytes of Internal Memory Area 0 contain the ARM processor exception vectors, in
particular, the Reset Vector at address 0x0.
Before execution of the remap command, the on-chip Flash is mapped into Internal Memory
Area 0, so that the ARM7TDMI reaches an executable instruction contained in Flash. After the
remap command, the internal SRAM at address 0x0020 0000 is mapped into Internal Memory
Area 0. The memory mapped into Internal Memory Area 0 is accessible in both its original
location and at address 0x0.
After execution, the Remap Command causes the Internal SRAM to be accessed through the
Internal Memory Area 0.
As the ARM vectors (Reset, Abort, Data Abort, Prefetch Abort, Undefined Instruction, Inter-
rupt, and Fast Interrupt) are mapped from address 0x0 to address 0x20, the Remap
Command allows the user to redefine dynamically these vectors under software control.
The Remap Command is accessible through the Memory Controller User Interface by writing
the MC_RCR (Remap Control Register) RCB field to one.
The Remap Command can be cancelled by writing the MC_RCR RCB field to one, which acts
as a toggling command. This allows easy debug of the user-defined boot sequence by offering
a simple way to put the chip in the same configuration as after a reset.
256M Bytes
0x0000 0000
0x0010 0000
0x0020 0000
0x000F FFFF
0x001F FFFF
0x002F FFFF
0x0FFF FFFF
0x0030 0000
Internal Memory Area 0
Internal Memory Area 1
Internal Memory Area 2
Undefined Areas
Internal SRAM
AT91SAM7S32 Preliminary
Internal Flash
(Abort)
1M Bytes
1M Bytes
1M Bytes
253M bytes
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