//Sending "YES" to Hyperterminal (or Tera Terminal) via Serial COM0 (SCI0) on HCS12 MCU Module
//The HCS12 MCU Module comes with one serial port with DB-9 connector ready to go. 
//On HCS12 MCU Module, the SCI0 pins of TX and RX of HCS12 are connected to DB-9 COM port
//It is done via a MAX232-compatible chip for converting TTL to RS232. 
//They SCI0 signales are accessed via both COM-USB and COM_EN jumpers. They are located close to USB connection.

//Make sure COM-USB and COM_EN jumpers are set. Also Make sure VB jumper for PWR_SEL is set too
//Also make sure the VB jumper for Power_SEL (next to power jack) is set since it is powered via USB cable
//connect the COM port of MCU Module to COM port of x86 PC via a via null serial cable. 
//If you do not have COM port on your x86 PC, then you need a USB-COM converter.
//Configure the Hyperterminal (for XP) or Tera Terminal (for Vista or Windows 7. See tutorial on this website).  

//Modfied from Example 10-9 in HCS12 textbook by Mazidi & Causey
//In codewarrior, Make sure you are in TBDML Mode before downloading 
//Press F7 (to Make), then F5(Debug) to downLOAD,and F5 once more to start the program execution
     

#include <hidef.h>      /* common defines and macros */
#include "derivative.h"      /* derivative-specific definitions */


void SerTx0(unsigned char);

void main(void) 
{
  /* put your own code here */
 
                    
    SCI0BDH=0x00;   //XTAL=4MHz  
    SCI0BDL=13;     //4MHz/2=2MHz, 2MHz/16=125,000 and 125,000/9600=13 
    SCI0CR1=0x00;
    SCI0CR2=0x0C;
    for(;;)
      {
        SerTx0('Y');
        SerTx0('E');
        SerTx0('S');
        SerTx0(' ');
        
      }

}

 
void SerTx0(unsigned char c)  //SCI0 (COM0 of HCS12 chip)
  {
    while(!(SCI0SR1 & 0x80));  //make sure the last bit is gone
    SCI0DRL=c;		       //before giving it another byte	
  }