I am presently testing the STR710 micro from STmicroelectronics using KEIL UV3 IDE. I have discovered from my own code (as well as the sample codes shipped with the compiler. Placing an IRQhandler AFTER the main() function causes the file not compile and showed lots of errors. But when placing the IRQHandler BEFORE or near the beginning of the program then it compiled fine. I have noticed some pre-compile directive in certain area #pragma userclass (CODE = default) and #pragma userclass (CODE =IRQ) resided in the c file. However, I had never be able to come up with a conclusive result by trying to place the above directives in various area of the file. My question is what is the RIGHT way to do in term of placing IRQhandler? void main (void) { } void IRQHandler_one() { } void IRQHanlder_two() { } The above arrangement NOT working