Hi, I bought a NUCLEO-H7A3ZI-Q, and I updated the firmware, from that on, I cant connect to the target whatever I do.

[SLori.2]

The port is showing in device manager and I can update/downgrade the firmware but I cant flash it. I had some similar problem with a bluepill but I put BOOT0 on 1 and erased the chip. After that it worked. I did the same with this board but it tells me cant connect to the target. I tried also with connect under reset. Nothing works...

[Tesla DeLorean · Accepted solution]

Don't use ST-LINK Utilities, want to be using STM32 Cube Programmer

If you get the LDO/SMPS settings messed up I'd suggest the following methodology for H7's

Put a jumper on board so you can pull/drive BOOT0 high. The NUCLEO-144's have VDD/BOOT0 pins next to each other to help facilitate.

With the jumper on power cycle the board a couple of time, complete disconnect USB, and reattach, do this twice counting out 5 seconds at each step.

Then when finally reconnected use STM32 Cube Programmer to Erase chip.

Remove jumper

Fix your code

Proceed

[SLori.2]

you are god, I will call you master Tesla DeLorean from now on. Jesus, I never thought to disconnect and reattach the board. Also yes, using ST LINK utilities was a mistake, thank you so much!

8)

[Tesla DeLorean]

The H7's in particular only latch options on power-up, the NRST is not a complete reset in the manner most expect. I think this is to help protect against glitching type attacks., or general robustness of the code protection methods, keys, etc.

I experienced this very early on, I had just received an engineering sample of the H747-DISCO, and promptly bricked it with some "hello world!" type code ported from the NUCLEO-H743 testing prior. The BOOT0 signal was some 0402 pad next to a BGA, and I told ST they needed a jumper or switch, because bricking them is almost a certainty.

[SLori.2]

Well I got the board and just updated the firmware and next time when I wanted to flash, just didn't recognized anymore ( the port was showing ). I got the same issue with the STM32F103C8T6 but with that it worked to erase the chip with ST LINK UTILITY. They definitely need to make a jumper for every board for BOOT 0 if this still happens...

[Tesla DeLorean]

If it keeps failing you're likely setting the SMPS/LDO or VOS settings wrong, or interfering with the debug pin operation, or powering down the logic.

static void SystemClock_Config(void)
{
  RCC_ClkInitTypeDef RCC_ClkInitStruct = {0};
  RCC_OscInitTypeDef RCC_OscInitStruct = {0};
 
  /*!< Supply configuration update enable */
  HAL_PWREx_ConfigSupply(PWR_DIRECT_SMPS_SUPPLY);
	
  /* The voltage scaling allows optimizing the power consumption when the device is
     clocked below the maximum system frequency, to update the voltage scaling value
     regarding system frequency refer to product datasheet.  */
  __HAL_PWR_VOLTAGESCALING_CONFIG(PWR_REGULATOR_VOLTAGE_SCALE0);
 
  while(!__HAL_PWR_GET_FLAG(PWR_FLAG_VOSRDY)) {}
...

[SLori.2]

Everything is working, thank you for all!