Hi.
I checked USB settings again but there was no problem.
In serial.py, I added a delay of 0.000001 at the end of the loop of read() method, not at the end of the write() method. In this way, I could flash simpleserial-aes-CW308_STM32F4.hex to CW308_STM32F4.
However, this was not sufficient to solve the original problem, calling capture_trace() sends a error saying target did not ack.
So, similar to the previous solution, I made same changes at the end of the loop of both write() and flush() methods.
Having done, I finally succeeded to acquire the trace of the target.
I think these temporary solutions are not perfect, so It is not strange when it breaks down.
For example, the amount of time.sleep should be adjusted delicately.
In the cases of 0.00001 or 0.0000001, It would not work properly.
***** IN CONCLUSION, *****
- change baud rate to 115200 on both the target side and the software side.
- add delay 0.000001 to the end of the while loop at write(), flush(), read() in
serial.py.
Thank you for your time and grateful consideration.
I wish my long long postings give some inspiration to the developers of CW hardware.