I am using a STM32G071. If I connect a STLINK to the uC, and then I disconnect it, also after a reset cycle, BOOT0 pin status is ignored and the boot happens always on Flash Memory instead of System Memory. Why? Is it normal?

ATPG · ‎2021-02-22

I want to use BOOT0 pin to select System Memory boot.

nBOOT0 = 0, nBOOT1 = 1, nBOOT_SEL = 0 bits in user config are well programmed.

Boot works well if my uC is coming from a POR or power cycle. But if I connect a ST-LINK to the uC and simply open the STM32CubeProgrammer application, and then I disconnect the programmer, also after a nRST hole the BOOT0 pin status is ignored and I cannot reach the system memory from boot anymore.

Uwe Bonnes · ‎2021-02-23

Did you check the option bits? BOOT0 can made to be ignored.

ATPG · ‎2021-02-23

Hi,

With STM32CubeProgrammer tihs is my option bits configuration.

I applied and then I read it back to check, and they re right.

nBOOL_SEL to 0 should guarantee the boot selection with boot0 pin.

The strange tihng is that happen just if I've connected the programmer before. If I power off and power on my board it works perfectly.