DocID027558 Rev 2

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AN4660

Hardware migration

26

1.3

System bootloader

The system bootloader is located in the system memory, programmed by ST during

production. It is used to reprogram the Flash memory using one of the following serial

interfaces.

Table 4 shows the supported communication peripherals by the system bootloader.

By default, in STM32F74xxx/F75xxx, when the boot from system bootloader is selected, the

code is executed from ITCM interface. It could be reprogrammed by option byte executed

from AXIM interface. For more details on system bootloader refer to AN2606.

Table 4. STM32F42xxx/F43xxx and STM32F74xxx/F75xxx bootloader communication

peripherals

System bootloader

peripherals

STM32F42xxx/F43xxx I/O pin

STM32F74xxx/F75xxx I/O pin

DFU

USB OTG FS (PA11 / PA12) in device mode

USART1

PA9 / PA10

USART3

PB10 / PB11 and PC10 / PC11

CAN2

PB5 / PB13

I2C1

NA

PB6 / PB9

I2C2

NA

PF0 / PF1

I2C3

NA

PA8 / PC9