Welcome to the club of hairpulling engineers. MPSIM does NOT DO USART simulation. PERIOD! I too wasted weeks of time developing serial code in MPSIM trying to figure out why it wasn't working as coded. When I fiaally got my hands on a live chip and burned my code, it worked PERFECTLY THE FIRST TIME! I no longer trust MPSIM because of the numerous errors I've found in simulating timers, CCP, etc. Robert.Rolf@UALberta.ca "Thomas C. Sefranek" wrote: > > Ken Webster wrote: > The simulator NEVER shows TXIF set! > But I've NEVER seen the ISR for the serial port get invoked! > (This is probably due to the fact that I've NEVER seen the serial port work in > the MPLAB.) Thats because the USART simulation is utterly broken. > It's like the serial port is NOT working! > > And BTW, I WISH I could have my code error pointed out to me, > I've spent 2 weeks trying to discover the error! One more week to go ;-{