Hi, I am using a 32.768 watch crystal connected to Timer1. I'd like Timer1 to generate an interrupt exactly each 1.0000 seconds. Should I load 16383 or 16384 to PR1? What it's not clear to me is if the value specified is ever reached in TMR1. Thanks, Mario -- http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist