ST STM32L4+ Series Reference Manual page 111

RM0432
(0x0800 0000). In other words, the Flash memory contents can be accessed starting
from address 0x0000 0000 or 0x0800 0000.
•
Boot from system memory: the system memory is aliased in the boot memory space
(0x0000 0000), but still accessible from its original memory space (0x1FFF 0000).
• Boot from the embedded SRAM1: the SRAM1 is aliased in the boot memory space
(0x0000 0000), but it is still accessible from its original memory space (0x2000 0000).
PH3/BOOT0 GPIO is configured in:
•
Input mode during the complete reset phase if the option bit nSWBOOT0 is set into the
FLASH_OPTR register and then switches automatically in analog mode after reset is
released (BOOT0 pin).
•
Input mode from the reset phase to the completion of the option byte loading if the bit
nSWBOOT0 is cleared into the FLASH_OPTR register (BOOT0 value coming from the
option bit). It switches then automatically to the analog mode even if the reset phase is
not complete.
Note: When the device boots from SRAM, in the application initialization code, you have to
relocate the vector table in SRAM using the NVIC exception table and the offset register.
When booting from the main Flash memory, the application software can either boot from
bank 1 or from bank 2. By default, boot from bank 1 is selected.
To select boot from Flash memory bank 2, set the BFB2 bit in the user option bytes. When
this bit is set and the boot pins are in the boot from main Flash memory configuration, the
device boots from system memory, and the boot loader jumps to execute the user
application programmed in Flash memory bank 2. For further details, please refer to
AN2606.
Physical remap
Once the boot pins mode is 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
memory remap register (SYSCFG_MEMRMP)
The following memories can thus be remapped:
• Main Flash memory
• System memory
• Embedded SRAM1 (192 Kbytes for STM32L4Rxxx and STM32L4Sxxx devices and
128 Kbytes for STM32L4P5xx and STM32L4Q5xx devices)
• FSMC bank 1 (NOR/PSRAM 1 and 2)
• OctoSPI (OCTOSPI1 or OSCTOSPI2) memory
Table 5. Memory mapping versus boot mode/physical remap
Addresses
0x2000 0000 - 0x2002 FFFF
0x1FFF 7000 - 0x1FFF FFFF
Boot/remap in Boot/remap in
main Flash embedded
memory SRAM 1
SRAM1 SRAM1
System System
memory/OTP/ memory/OTP/
Options bytes Options bytes
RM0432 Rev 6
in the SYSCFG controller.
Boot/remap in
Remap in
system
FSMC
memory
SRAM1 SRAM1
System System
memory/OTP/ memory/OTP/
Options bytes Options bytes
SYSCFG
(1)
Remap in
OCTOSPI
SRAM1
System
memory/OTP/
Options bytes
111/2301
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