DocID027559 Rev 5 27/54
AN4661 Boot configuration
53
4 Boot configuration
4.1 Boot mode selection
In the STM32F7 Series, two different boot spaces can be selected through the BOOT pin
and the boot base address programmed in the BOOT_ADD0 or BOOT_ADD1 option bytes
as shown in the
Table 2.
The BOOT_ADD0 and BOOT_ADD1 address option bytes allow to program any boot
memory address from 0x0000 0000 to 0x2004 FFFF which include:
• All the Flash memory address space mapped on ITCM or AXIM interface.
• All the RAM address space: ITCM, DTCM RAMs and SRAMs mapped on AXIM
interface.
• The system memory bootloader.
The BOOT_ADD0 / BOOT_ADD1 option bytes can be modified after the reset in order to
boot from any other boot address after the next reset.
If the programmed boot memory address is out of the memory mapped area or a reserved
area, the default boot fetch address is programmed as follows:
• Boot address 0: ITCM-FLASH at 0x0020 0000
• Boot address 1: ITCM-RAM at 0x0000 0000
When the Flash level 2 protection is enabled, only boot from the Flash memory (on ITCM or
AXIM interface) or the system bootloader will be available. If the already programmed boot
address in the BOOT_ADD0 and/or BOOT_ADD1 option bytes is out of the memory range
of the RAM address (on ITCM or AXIM), the default fetch will be forced from the Flash
memory on ITCM interface at the address 0x00200000.
Table 2. Boot modes
Boot mode selection
Boot space
BOOT
pin
Boot address
option bytes
0 BOOT_ADD0 [15:0]
– Boot address defined by the user option byte BOOT_ADD0[15:0]
- ST programmed value: Flash on ITCM at 0x0020 0000
1 BOOT_ADD1 [15:0]
– Boot address defined by the user option byte BOOT_ADD1[15:0]
- ST programmed value: System bootloader at 0x0010 0000
To Next Page
Loading...
Need help?
General
