----- Original Message ----- From: "Andrew E. Kalman" To: Sent: Friday, June 29, 2001 6:12 PM Subject: Re: [PIC]: 16c73 RA4 as I/O will not work > Andy Warren wrote: > > >Explicitly writing 1's and 0's, as Roy originally did, ensures that > >he's not having a read-mofdify-write problem... Which he WOULD have > >had if he used your code with his original hardware (i.e., without a > >pullup on RA4). > > Actually, his code compiles to bcf and bsf instructions, too, which > are RMW instructions. Perhaps that's the original source of his > problems? Yes, but the bit being set or cleared is the one in question, so it can't cause the typical RMW problem. The RMW problem with BCF/BSF happens on _other_ bits within the same port. Bob Ammerman RAm Systems (contract development of high performance, high function, low-level software) -- http://www.piclist.com#nomail Going offline? Don't AutoReply us! email listserv@mitvma.mit.edu with SET PICList DIGEST in the body