STM32F303 internal bootloader does not work (if exiting from a reset)

[Davide Rizzi]

Posted on September 11, 2017 at 12:47

Part number is STM32F303CC.

A 24 MHz oscillator output is connected to PF0 pin.

Exiting from reset (either via nRST pin or SCB_AIRCR SYSRESETREQ bit), and having BOOT0 pulled up and USB cable connected, the bootloader waits forever for RCC_CR HSERDY bit to become 1.

The same identical problem presents with BOOT0 low, thus starting from Flash and jumping to the internal bootloader (SP@0x1FFFD800 and Reset@0x1FFFD804) - that is what we want to do.

BUT If I power cycle the board, everything works as expected (USB DFU bootloader up and running).

Is the bootloader supposed to start following a reset (as it is described on the refman and as it happens on other parts we have worked with)?

Am I missing something?

[Tesla DeLorean · Accepted solution]

Posted on September 11, 2017 at 13:16

>>The same identical problem presents with BOOT0 low, thus starting from Flash and jumping to the internal bootloader (SP@0x1FFFD800 and Reset@0x1FFFD804) - that is what we want to do.

Do you map the ROM so that is shadows into the zero address space? SYSCFG mapping register