I put the monitor-251 code in the target device, and connect to pc with a seiral-cable. The connection is fail, and I check the monitor-251 code. I find the monitor-251 is waiting for receiveing the data-byte(D6h) from PC. But PC always send the data-byte(D7h), so the connection is always failed. Could you tell me the monitor-251 of KeilC251 is usable or not? Or there're some settings about PC or monitor-251 I should notice. Thanks for your great help.
The MON251 Target Interface of uVision2 sends a 0xD6 first, the followed by several 0xD7. So you should check why the first 0xD6 is ignored by your hardware. It be possible to create an Monitor-251 even with the Eval Version.