r brooks

SCI transmission

Discussion created by r brooks on Mar 11, 2008
Latest reply on Mar 14, 2008 by Jim Donelson
I am working with the Adapt9s12XD512. When I try to transmit from the SCI pins, I can't even get any kind of signal on the oscilloscope.  I get a very clean looking 5V signal.  Do I need something else to make this work?
Here is my code (using codewarrior):
 SCI0BD = 0x0068;      //seems like I've tried every possible value for these...
SCI0CR1 = 0x00;       
SCI0ASR1 = 0x00;    
SCI0ACR1 = 0x00;    
SCI0ACR2 = 0x00;
SCI0CR2 = 0x0C;
  for(;:smileywink: { //* wait forever / 
  while((SCI0SR1 & 0x80) == 0);
  g_temp = SCI0SR1; 
  SCI0DRL = 0xff;
  while((SCI0SR1 & 0x80) == 0);      //also tried !(this)
  g_temp = SCI0SR1; 
  SCI0DRL = 0x00;
(I also tried many different values for all the port S registers, which seemed to have no effect.)
What am I missing?