Hello, I'm trying to write a Function that reads a character from RS232 (trival?). I'm using 80c552, Serial_Mode=1. I think the baudrate is set correct (I can transmit data to the PC). The Problem is, S0BUF is allways empty. I tried it on the simulator too. I paste my code:
CLR RI JNB RI,$ ; waiting for character MOV R7, S0BUF ; <- here S0BUF is ALLWAYS 0x00 RET
Please do a simple loopback test on both the ends (PC and your 80c552). This will isolate the problem much better. Can you post the complete code, if possible?