Boot Configuration; Boot Mode Selection; Table 3. Boot Modes - ST STM32F74 Series Getting Started

AN4661
4

Boot configuration

4.1

Boot mode selection

In the STM32F74xxx/STM32F75xxx devices, 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
Boot mode selection
BOOT pin
0
1
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 Flash memory address space mapped on ITCM or AXIM interface.
• All 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 reset in order to boot
from any other boot address after 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 flash level 2 protection is enabled, only boot from Flash memory (on ITCM or AXIM
interface) or 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 or RAM
address (on ITCM or AXIM) the default fetch will be forced from Flash memory on ITCM
interface at address 0x00200000.
STM32F74xxx/STM32F75xxx
Boot address
option bytes
– Boot address defined by user option byte BOOT_ADD0[15:0]
BOOT_ADD0 [15:0]
– Boot address defined by user option byte BOOT_ADD1[15:0]
BOOT_ADD1 [15:0]
DocID027559 Rev 2
Table 3.

Table 3. Boot modes

- ST programmed value: Flash on ITCM at 0x0020 0000
- ST programmed value: System bootloader at 0x0010 0000
Boot configuration
Boot space
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