C.3.2. Configurable area of memory map

The addressing of memory is partially configurable. Reasons for configuring memory addresses include:

Example memory map

The ARM926EJ-S and ARM1136JF-S cores have the following characteristics:

  • The TCM location is configurable. Do not map the TCM to an area of memory that is used by control registers or memory-mapped IO. Also, the TCM I-RAM and TCM D-RAM regions must not overlap.

    Refer to the Technical Reference Manual for the processor core for details on using the CP15 registers to configure TCM and cache.

  • The MMU can map physical memory to a different logical address.

Table C.1 shows a typical memory map with TCM present and enabled.

Table C.1. Example of 32KB TCM

Address rangeSizeDescription

0x000000000x00007FFF

32KBSSRAM (REMAP=0) or flash (REMAP=1).

0x000080000x0000FFFF

32KBTCM I-RAM (address can be assigned to any 32KB boundary) If TCM is disabled, this space is filled by SSRAM or flash.

0x000100000x00017FFF

32KBSSRAM (REMAP=0) or flash (REMAP=1).

0x000180000x0001FFFF

32KBTCM D-RAM (address can be assigned to any 32KB boundary) If TCM is disabled, this space is filled by SSRAM or flash.

0x000200000x000FFFFF

896KBSSRAM (REMAP=0) or flash (REMAP=1).
0x001000000x0FFFFFFF256MBSDRAM (repeats physical memory to fill space) Part of the first SDRAM image is masked by the SSRAM image.

0x100000000x107FFFFF

8MB

Core Module registers.

0x108000000x10FFFFFF

8MBOn-board SSRAM alias (repeats physical memory to fill space).

0x110000000x1FFFFFFF

256MBPeripherals

0x200000000x23FFFFFF

64MBBoot code alias

0x240000000x24FFFFFF

16MBBaseboard flash memory (contains user code and boot code).

0x250000000x27FFFFFF

48MBUnused (larger sized baseboard flash devices occupy this area).

0x280000000x7FFFFFFF

2.3GBReserved (abort if accessed).

0x800000000x8FFFFFFF

256MBSDRAM (alias).

0x900000000xBFFFFFFF

2.3GBReserved (abort if accessed).

0xC00000000xCFFFFFFF

256MBCP control registers and APB peripherals.

0xD00000000xFFFFFFFF

768MBReserved (abort if accessed).

Table C.2 shows a typical memory map for no TCM.

Table C.2. Example of TCM disabled or no TCM

Address rangeSizeDescription

0x000000000x000FFFFF

1MB(REMAP=1) SSRAM or (REMAP=0) flash.
0x001000000x0FFFFFFF256MBSDRAM (repeats physical memory to fill space) Part of first SDRAM image is masked by SSRAM or flash.

0x100000000x107FFFFF

8MB

Core Module registers.

0x108000000x10FFFFFF

8MBOn-board SSRAM alias (repeats physical memory to fill space).

0x110000000x1FFFFFFF

256MBPeripherals

0x200000000x23FFFFFF

64MBBoot code alias

0x240000000x24FFFFFF

16MBBaseboard flash memory (contains user code and boot code).

0x250000000x27FFFFFF

48MBUnused (larger sized baseboard flash devices occupy this area).

0x280000000x7FFFFFFF

2.3GBReserved (abort if accessed).

0x800000000x8FFFFFFF

256MBSDRAM (alias).

0x900000000xBFFFFFFF

2.3GBReserved (abort if accessed).

0xC00000000xCFFFFFFF

256MBCP control registers and APB peripherals.

0xD00000000xFFFFFFFF

768MBReserved (abort if accessed).
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