>>Can someone tell me what's instruction set test? >Why do you want to do this? Performing an instruction test on a single chip It sounds like a requirement of safety testing labs, as has been discussed here before in regard to queries about ROM checksums. It seems the funny sort of test they might require. -- http://www.piclist.com hint: PICList Posts must start with ONE topic: [PIC]:,[SX]:,[AVR]: ->uP ONLY! [EE]:,[OT]: ->Other [BUY]:,[AD]: ->Ads