some (5-10%) STM32G0 can't program through native UART bootloader

[imranaftab]

Hello,

I am using STM32G0B1cbt6. And I am using native bootloader to update firmware. But in some boards not able to update firmware, it is giving below error:

And when we replaced the MCU then bootloader started working normally.

 The failure percentage is like out of 100, in 5 to 10 MCUs we are facing problem. 

What could be the reason? And how it can be resolved?

[Andrew Neil]

Is this on a custom board?

If so, please post the schematic.

See: How to write your question to maximize your chances to find a solution.

[imranaftab]

Yes, this is a custom board.

I am attaching the schematic below. Which running on standard 3.3V supply.

Is there any way to check if the bootloader is corrupted and if corrupted is there any way to reprogram it? 

[Uwe Bonnes]

ASsyou use HSI, maybe HSI may be slightly out of range.Check serial communication with a scope to check for frequency mismatch. Try heating or cooling the non responding devices to move HSI frquency

B,t,w, NRST Pullup is deprecated

[Himanshu_Dhiman]

Hello,

We have tried the below methods and no resolution found.

1. Remount same MCU: Some started working, some not working
2. Replaced new MCU: Some started working, some not working
3. Boot 0 pin HIGH at startup: Some started working, some not working
4. Boot 0 pin LOW at startup: Some started working, some not working
5. NRST pull up resistor removed: Some started working, some not working
6. Connected ST Link programmer and tried OTA: Not working
7. Observed Boot 0 and NRST with scope: No change while updating.