DocID018909 Rev 11
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RM0090
Memory and bus architecture
112
Physical remap in STM32F42xxx and STM32F43xxx
Once the boot pins are selected, the application software can modify the memory
accessible in the code area (in this way the code can be executed through the ICode bus in
place of the System bus). This modification is performed by programming the
SYSCFG memory remap register (SYSCFG_MEMRMP)
in the SYSCFG controller.
The following memories can thus be remapped:
•
Main Flash memory
•
System memory
•
Embedded SRAM1 (112 KB)
•
FMC bank 1 (NOR/PSRAM 1 and 2)
•
FMC SDRAM bank 1
Table 3. Memory mapping vs. Boot mode/physical remap
in STM32F405xx/07xx and STM32F415xx/17xx
Addresses
Boot/Remap in
main Flash memory
Boot/Remap in
embedded SRAM
Boot/Remap in
System memory
Remap in FSMC
0x2001 C000 - 0x2001 FFFF
SRAM2 (16 KB)
SRAM2 (16 KB)
SRAM2 (16 KB)
SRAM2 (16 KB)
0x2000 0000 - 0x2001 BFFF
SRAM1 (112 KB)
SRAM1 (112 KB)
SRAM1 (112 KB)
SRAM1 (112 KB)
0x1FFF 0000 - 0x1FFF 77FF
System memory
System memory
System memory
System memory
0x0810 0000 - 0x0FFF FFFF
Reserved
Reserved
Reserved
Reserved
0x0800 0000 - 0x080F FFFF
Flash memory
Flash memory
Flash memory
Flash memory
0x0400 0000 - 0x07FF FFFF
Reserved
Reserved
Reserved
FSMC bank 1
NOR/PSRAM 2
(128 MB Aliased)
0x0000 0000 -
0x000F FFFF
(1)(2)
Flash (1 MB) Aliased
SRAM1 (112 KB)
Aliased
System memory
(30 KB) Aliased
FSMC bank 1
NOR/PSRAM 1
(128 MB Aliased)
1. When the FSMC is remapped at address 0x0000 0000, only the first two regions of bank 1 memory controller (bank 1
NOR/PSRAM 1 and NOR/PSRAM 2) can be remapped. In remap mode, the CPU can access the external memory via
ICode bus instead of System bus which boosts up the performance.
2. Even when aliased in the boot memory space, the related memory is still accessible at its original memory space.
Table 4. Memory mapping vs. Boot mode/physical remap
in STM32F42xxx and STM32F43xxx
Addresses
Boot/Remap in
main Flash memory
Boot/Remap in
embedded SRAM
Boot/Remap in
System memory
Remap in FMC
0x2002 0000 - 0x2002 FFFF
SRAM3 (64 KB)
SRAM3 (64 KB)
SRAM3 (64 KB)
SRAM3 (64 KB)
0x2001 C000 - 0x2001 FFFF
SRAM2 (16 KB)
SRAM2 (16 KB)
SRAM2 (16 KB)
SRAM2 (16 KB)
0x2000 0000 - 0x2001 BFFF
SRAM1 (112 KB)
SRAM1 (112 KB)
SRAM1 (112 KB)
SRAM1 (112 KB)
0x1FFF 0000 - 0x1FFF 77FF
System memory
System memory
System memory
System memory
0x0810 0000 - 0x0FFF FFFF
Reserved
Reserved
Reserved
Reserved
0x0800 0000 - 0x081F FFFF
Flash memory
Flash memory
Flash memory
Flash memory