If the variables are single-byte then it's possible that there won't be a problem, but it ultimately depends on whether you read/write the variable in the interrupt, read/write it in the other function, and exactly what you're doing with it in both locations. And, of course, it ultimately depends on the code that the compiler generates in both places.

Trying to disable the timer interrupt might be a good test, but just letting the modified version run for a few weeks isn't going to prove that the problem is fixed. If possible, it would be helpful if you could post the interrupt source code and the main source code that share a global variable. If you choose to post the source code, please use the < PRE> and < /PRE> tags to post your code.

Regards,
Craig Steiner