Hi Olin, > Right. I see no such opcode in the data sheet. What do you expect it to > do? Actually I was expecting it will perfrom MOVLW 0x00 as what I did in 16 series. I got PICDEM 2+ demo board which came together with my new ICD2. When I was looking inside the source, I found that it is written for a PIC18F452 device. But it is fail when I try to compile. I assume that is a bug or something else going wrong with my MPLAB v6.40. But now I know it isn't. Thanks a lot for your responces. WH Tan -- http://www.piclist.com hint: To leave the PICList mailto:piclist-unsubscribe-request@mitvma.mit.edu