STM32F0 does not run standalone

mmensch · ‎2013-08-12

Posted on August 12, 2013 at 13:27

Hi,

on my STM32F0 discovery board I configured the clock source to be HSI with a system_stm32f0xx.c generated by the clock configuration tool . That seemed to run like it should. Now I pulled JP2 and supplied Vdd pin with external 3,3V expecting only the STM32F0 to run while the USB -> SWD uC would not run. But that failed, both don't run although I can measure 3,3V at the Vdd pins of STM32F0. What else than clock in is coming from the USB -> SWD uC needed to run STM32F0? Is there a way the STM32F0 falls back to HSE?

Any hints are welcome.

Thank you

Martin

mmensch · ‎2013-08-13

Posted on August 13, 2013 at 11:06

Hi,

I found out myself:

NRST of STM32F0 is driven by the USB->SWB uC. If this one is not powered the clamping diodes hold the pin low and force STM32F0 into reset. I opened SB19 and it worked. I would suggest another jumper aside JP2.

Martin