The code I wrote on the board Nucleo-L522ZE-Q has time interruption and controls the LED to flash. It is successful. After being applied to my own circuit board by ST-LINK , the time interruption cannot occur. I want to know why?

[XZou.1]

I run it in debugging.​

[Tesla DeLorean · Accepted solution]

Ok, and what have you learned in the debugger, having stepped in from Reset_Handler ?

Check your design for BOOT0 pin/settings.

Check your HSE clock source is present and starts properly.​

[XZou.1]

Thank you. I solved it。BOOT0 pin must be set Low。I opened it。:face_with_tears_of_joy:

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