STM32F7 Debugging Hardware

[Ray Mendoza]

Posted on July 31, 2017 at 20:49

Hello all,

I have created a new PCB with a STM32F746ZG chip but the issue is that I am able to upload the GPIO IO Toggle example from the NucleoF746 folder but the LEDs do not blink after uploading. I have tried making my design similar to Nucleo-F746ZG.

My design uses the following parts for the oscillators, which are different:

   NX3225GD-8.000M-STD-CRA-3 with 15pf capacitors

   NX3215SA-32.768K-STD-MUA-8 with 2pf capacitors

Using the debugger, I am able to see that the chip is able to step through the code. I have probed the pins on the chip to see if there are any changes but so far there are none.

So I was wondering if the oscillator has anything to with why the LED does or does not turn on. I do believe it is the hardware because I am testing the firmware with the nucleo, which currently works. I have accounted the firmware changes below so my PCB uses the external oscillator, which I hope I did correctly.

  RCC_OscInitStruct.OscillatorType = RCC_OSCILLATORTYPE_HSE;

//  RCC_OscInitStruct.HSEState = RCC_HSE_BYPASS;    RCC_OscInitStruct.HSEState = RCC_HSE_ON;    RCC_OscInitStruct.HSIState = RCC_HSI_OFF;  RCC_OscInitStruct.PLL.PLLState = RCC_PLL_ON;  RCC_OscInitStruct.PLL.PLLSource = RCC_PLLSOURCE_HSE;  RCC_OscInitStruct.PLL.PLLM = 8;  RCC_OscInitStruct.PLL.PLLN = 432;  RCC_OscInitStruct.PLL.PLLP = RCC_PLLP_DIV2;  RCC_OscInitStruct.PLL.PLLQ = 9;  ret = HAL_RCC_OscConfig(&RCC_OscInitStruct);

If you want anymore information, just ask!

Thank you!

#stm #stm32f7 #blink #debugger

[Tesla DeLorean · Accepted solution]

Posted on July 31, 2017 at 20:55

Step One, just run it from the HSI that was running until the point you turned it off.

Prove that it works, then clock the PLL from the HSI, prove that works. Then come back, enable the HSE while still running from the HSI/PLL, ie don't turn them off, pipe the HSE clock out of the MCO pin, confirm that looks solid, and check the oscillator. Sticking probes on the oscillator directly will change circuit characteristics, so better to look indirectly first. If the HSE doesn't come ready check the specs for the crystal again, and the capacitors chosen/placed.

[Ray Mendoza]

Posted on August 31, 2017 at 00:27

Hey Clive,

I know this is late.

Thank you for the steps to debugging. I have it up and running now. I just wanted to reply to say thanks for the help!!!!