//Displaying ATD0 channel 1 (POT) on 8 LEDs of PORTA for Freescale Project Board with HCS12 MCU module 

//Modified from Program 13-1 of HCS12 textbook by Mazidi & Causey 
//In HCS12 MCU Module, XTAL=4MHz, Bus Freq. =2MHz. Then divivde it by 2 to get 1MHz for conversion freq. 
//ATD0 channel 1 (AN01) is connected to POT. The POT (RV1) is located on the bottom corner left side of the Student Project Board.

//Change the POT to see the changes on LEDs of PORTA

//The lower 4 bits of PA3-PA0 are connected to LEDs(LED1-LED4 on J10) permanently 
//and must be enabled by clearing bit P4 of PORTP. 
//MAKE SURE both jumpers for LED and POT are set. LED and POT jumpers are part of group of jumpers called UFEA right next to the Buzzer 

//To have 8 LEDs, we must also connect 4 wires from LED5-LED8 (J10) to pins PA7-PA4 via J6 connector

//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 MSDelay(unsigned int);
void main(void) 
 {
  /* put your own code here */
  
    
    DDRA = 0xFF;    //PORTA as output since LEDs are connected to it
    DDRP = DDRP | 0b00010000;  //on Project Board, the lower 4 bits of PA3-PA0 are connected to LEDs(LED1-LED4) permanently
    PTP = PTP & 0b11101111;    //and must be enabled by clearing bit P4 of PORTP
                 //on Project Board,we need to connect 4 wires from LED5-LED8 (J10) to pins PA4-PA7 via J6 connector (pins 25,27,29,31)

   DDRP = DDRP | 0b00001000; //We need to make P3 bit of PORTP as output for the POT                         
   PTP = PTP | 0b000001000; //The POT is connected to AN01 (ADC0 chan 1) and must be enabled by setting high bit P3 of PORTP
     
    
 ATD0CTL2 = 0x80;     //Turn on ADC,..No Interrupt
    MSDelay(1);	      //optional 	
    ATD0CTL3 = 0x08;  //one conversion, no FIFO
    ATD0CTL4 = 0xE0;  //8-bit resolu, 16-clock for 2nd phase,
                      //prescaler of 0 for Conversion Freq=1MHz  
      for(;;)
      {
        ATD0CTL5 = 0x81;  //Channel 1 (right justified, unsigned,single-conver,one chan only) 
			  
        while(!(ATD0STAT0 & 0x80));
        PORTA = ATD0DR0L;  //dump it on LEDs
    
      //MSDelay(2);     /optional
  
    }
    

  }

 void MSDelay(unsigned int itime)
  {
    unsigned int i; unsigned int j;
    for(i=0;i<itime;i++)
      for(j=0;j<311;j++);
  }