Hi,

On E2E world wide, please use English.

For L1306, the clock initialization is all controlled by Sysconfig not from C code.  Normally, no mater using SYSOSC with or without calibration, you should not meet this problem.

To debug the problem, my suggestion is that:

• Use Sysconfig to disable BSL to make sure the code will not jump to BSL
• Output SYSOSC clock and check its frequency. If the frequency is not right, change SYSOSC to internal clock and make a try again.
• Please use oscillosope to catch the signal and post it to e2e to let us analysis together

Eason

Thank you very much.

If there is any update, please let me know. I also want to know why it happens.