I debug it the second day, and what I found, IPSR register set its content to 32 after first call to the function in the main(). What is more interesting, it doesn’t happen all the day, sometimes IPSR is clear (i.e. contents 0), other time it contents 32. This is very interesting problem. If I am able to ensure that this is a bug concerning wrapper, I will report that to the supplier of CMSIS wrapper.