Using the Dallas 80C320 with Keil evaluation software. I am seeing the data sent to the Uc echoed back to the sender. I am not intentionally echoing the data. I can't find any mention of this in the data sheets or the Keil website. Anyone have any ideas?
Have you checked the following: * Local Echo is turned on in your terminal program. * You're accidentally writing received characters to SBUF. * You have a hardware ECHO somehow built-in to your target board. (I don't have a great idea of how you'ld accidentally do this:-) Jon
It can be very easy to build in an accidental hardware echo. Crosstalk from the transmit line to the receive line is the usual culprit.
Oops, I shoulda remembered this. In this case, the echo is done by the Keil getchar routine. Note that this is documented in the C51 User's Guide. The following knowledgebase article discusses this as well as a workaround. http://www.keil.com/support/docs/1791.htm Jon