More RS232 issues on S08QG8

Discussion created by ROB LUND on May 15, 2007
Latest reply on May 22, 2007 by ROB LUND
Continuing from where I left off with getting RS232 communication via the SCI on a MC9S08QG8 target board, I have some new questions. :smileyhappy:

Getting that code working on my DEMO board, I now am in the process of porting it into my target board (same MCU).

I was having difficulty interfacing with a low-voltage micro-power RS232 transceiver (ICL3232). So I did some sleuthing on the DEMO board and its transceiver is wired differently than mine.

Specifically, the SCI pins are backwards. The good wizards at Axiom (the makers of the DEMO board) have PTB1 on a T1in pin (transmit out to RS232) and PTB0 on a R1out pin (receive from RS232).

But my MC9S08QG8 datasheet, rev 1.01, 10/2005, page 192 clearly shows the SCI port block diagram as having PTB1 as receiver and PTB0 as transmitter, both in the arrow direction and the label on the lines. Yet, the labels of the port pins have these titles reversed.

What's going on here?