OK, my bad. I guess I didn't understand what the internal clock frequency was, and I was using so many prescalers it had a on/off time of about 30 minutes. It is working, thanks for your response though! Regards, Bob ----- Original Message ----- From: "Tony Nixon" To: Sent: Thursday, December 04, 2003 8:33 PM Subject: Re: [PIC]:Interrputs will not re-enable on 16F819 > Is it the T0IF or T0IE flag that you are clearing. It should be T0IF. > > Tony > > Bob Setbacken wrote: > > >Hi, i have read similar posts but not seen an answer to this. I am trying to learn how to use interrupts on this device. I initialize everything in the main prog, then simply loop. The interrupt routine is driven by TMR0 overflow, and TMR0 is driven by the internal clock w/prescaler. There is a nested countup in the interrupt service, that should toggle all the pins of port B every time the count register overflows. > > > >I am using Warp13 w/MPLAB. When I simulate this and put breakpoints in the ISR, everything looks great. I am using the state saving methods suggested on this site. I clear the TMR0 flag in the interrupt, and return with a RETFIE. > > > >When I run the program in hardware, it flashes all teh LED's once, and then never again. If I DONT clear the TMR0 flag, and run the program, it looks like it is working, but I think it is just always returning to the ISR due to the flag being set and the interrupts enabled. I don't think TMR0 is driving the program anymore. > > > >Any suggestions? > > > >Thanks, > > > >Bob > > > >-- > >http://www.piclist.com hint: The list server can filter out subtopics > >(like ads or off topics) for you. See http://www.piclist.com/#topics > > > > > > -- > http://www.piclist.com hint: The list server can filter out subtopics > (like ads or off topics) for you. See http://www.piclist.com/#topics > -- http://www.piclist.com hint: The list server can filter out subtopics (like ads or off topics) for you. See http://www.piclist.com/#topics