//Testing Push Button (PB1 and PB2) Switches on Student Project Board. 
//This program gets status of Push Button SW of PB1-PB2 and sends it to LEDs on PORTA 
//Using HCS12 MCU Module with Freescale Student Project Board  
//HCS12 MCU Modules come with USB-BDM and ready to be used with CodeWarrior IDE


//The lower 4 bits of PA3-PA0 (pins of HCS12 CPU) are connected to LEDs(LED1-LED4 on J10) permanently
//and must be enabled by clearing bit P4 of PORTP. Also set the LED jumper on UFEA jumpers next to Buzzer
//We also need to connect 4 wires from LED5-LED8 (J10) to pins PA7-PA4 via J6 connector 

//The lower 2 bits of PP1-PP0 (pins of HCS12 CPU) are connected to push buttons of PB1 and PB2 permanently
//and must be enabled by clearing bit P5 of PORTP. Also set the PB jumper on UFEA jumpers next to Buzzer



//On HCS12 MCU Module itself 
//a)MAKE SURE BOTH jumpers for PP0 and PP1 are removed (SW1 and SW2).
//b)Also Make sure 8 Jumpers (SW3-1 to SW3-4 and LED1-LED4) on HCS12 MCU module are also removed  
            

          
//Written and tested by M. Mazidi using Examples in chap. 7 of 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 MSDelay(unsigned int);
void main(void) 
{
  /* put your own code here */
  
   unsigned char x; 

    DDRA = 0xFF;    //PORTA as output since LEDs are connected to it
    DDRP = DDRP | 0b00110000;  //Make PP4 and PP5 as output. On the Project Board, a)the lower 4 pins of PA3-PA0 are connected to LEDs(LED1-LED4) 
    PTP = PTP & 0b11001111;    //and b)the PP0 and PP1 pins are connected to PB1 and PB2 push buttons. c) They mut be enabled by clearing pins P4 and P5 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)
        
       
    for(;;) 			
      {
        x=PTP;    //Get data from push button of push button of PB1 and PB2 
        x=x&0b00000011;    //mask the unwanted bits
        PORTA = x;       //send it to PORTA
        MSDelay(1); //optional
      }
 
}


//The HCS12 MCU Module works with XTAL=4MHz 
//Freq. for Instruction Clock Cycle (Bus Freq.) is 2MHz (1/2 of 4MHz). 
 void MSDelay(unsigned int itime)
  {
    unsigned int i; unsigned int j;
    for(i=0;i<itime;i++)
      for(j=0;j<313;j++);    //1 msec. tested using Scope
  }