Hello all, My code is based on RTX-Full ver5.1. I minimize the code to interrupt function and a task. When the micro receives int0, the interrupt function is activated and what he do is to read port0 data to global variable. At the second interrupt, the interrupt function compare between port0 data and the temporary variable. If the are the same, the interrupt function sends a signal to RCV task, if not he sets P1.6 low. I implement this code in RTX-Full and after several interrupts where the comparation passed, the comparation fails and P1.6 goes low. I implement the same code in RTX-Tiny and the comparation never fails. Any ideas? Thanks a lot, Reuven