In the debugging mode,if I wanted "step into" the function within the switch statement it just skip and does not "step into" the function. It is very strange. Any one can help this. very much appreciated. Thanks
I have moved your query to the Keil tools forum, where you are more likely to get an appropriate audience for your query. However I recommend posting to the STM32 specific forum below for the best audience.
This is really a completely STMicroelectronics related question, you could probably get relevant information by posting on the STMicroelectronics forum.