Hi Sam TMR0 is shut down, during sleep, so therefore you cannot use the TMR0 interrupt to wake it up. You can wakeup your PIC through on of the following.: 1: WDT (if enabled) 2: Interrupt from RB0/Pin on change/E2PROM WR complete. 3: Reset on /MCLR pin Henrik Nowak -----Oprindelig meddelelse----- Fra: Sam S Man [SMTP:samsman@TM.NET.MY] Sendt: 24. maj 1999 16:52 Til: PICLIST@MITVMA.MIT.EDU Emne: F84 won't wake up Hi to all! My F84 just won't wake up from sleep. TMR0 supposed to wake it up but nothing happenned. All other ints works fine. Initially, of course tmr0 was loaded with 255 to make it roll over to create the overflow interrupt but nothing happens. What could it be? Sam http://www.samsman.click2site.com