In SX Microcontrollers, SX/B Compiler and SX-Key Tool, bean wrote: Vertex78, A couple points. 1) First of all you need to specify OPTIONX on the device line or else you won't get any interrupts. 2) Do you realize that XOR rb,rb is the same as CLR rb ? I think maybe you want XOR rb,#$FF. 3) Your !OPTION setting is for 1:2 prescaler. 4) When single stepping, the debugger will NOT execute the interrupt. But you can put a breakpoint in the interrupt and the debugger will stop at it. I hope this helps... Bean. ---------- End of Message ---------- You can view the post on-line at: http://forums.parallax.com/forums/default.aspx?f=7&p=1&m=111249#m111305 Need assistance? Send an email to the Forum Administrator at forumadmin@parallax.com The Parallax Forums are powered by dotNetBB Forums, copyright 2002-2006 (http://www.dotNetBB.com)