//Toggling PORTT in C Language for TWR-HCS12G128 Tower module using CodeWarrior 
//On TWR-S12G128 Tower module, 4 green LEDs are connected to PT7-PT4 
//They are active LOW. Make sure the jumers for all 4 LEDs are set
//Modified and tested by Mazidi from Example 7-7 of Mazidi & Causey HCS12 textbook

//Use F7 to Make, F5 (Debug) to download, and F5 (Start) to run the program

//In CodeWarrior,make sure you are in Open Source BDM when downloading and running. 

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


void MSDelay(unsigned int);
void main(void) 
{
  /* put your own code here */
  
    unsigned int size=300;

    DDRT = 0xF0;    //PT7-PT4 as output since LEDs are connected to it
    for(;;) 			
      {
        PTT = 0x50;
        MSDelay(size);    
        PTT = 0xA0;
        MSDelay(size);
      }
 
}

//j is for 1 msec delay. Not Measured by Scope yet 
//Use Scope and modify j to get an exact value for 1 msec

 void MSDelay(unsigned int itime)
  {
    unsigned int i; unsigned int j;
    for(i=0;i<itime;i++)
      for(j=0;j<1000;j++);    //Approximatley 1 msec. NOT tested using Scope
  }