> Actually you don't manually ACK, you set CKP and it ACKs for you. You've really confused things. On a write (master to slave), the MSSP in slave mode will automatically send the ACK bit. CKP is only used on a read by a slave, and it has nothing to do with ACK. On a read in master mode the ACK must be explicitly sent, but that is done with the ACKEN bit (if I remember right, I'm home now and don't have a manual in front of me). ******************************************************************** Olin Lathrop, embedded systems consultant in Littleton Massachusetts (978) 742-9014, olin@embedinc.com, http://www.embedinc.com -- http://www.piclist.com#nomail Going offline? Don't AutoReply us! email listserv@mitvma.mit.edu with SET PICList DIGEST in the body