#include <hidef.h>      /* common defines and macros */
#include <mc9s12c128.h>     /* derivative information */
#pragma LINK_INFO DERIVATIVE "mc9s12c128"

/* 
  ECE348, Spring 2016
  Group ##
  <name1> <andrewid1>
  <name2> <andrewid2>

  Carnegie Mellon 18-348   lab 01   program 2 -- C version

  This program uses the switches and LEDs on the microcontroller module itself. When SW1
  is pressed, LED1 turns on and LED2 turns off until SW2 is pressed. When
  SW2 is pressed LED2 turns on and LED1 turns off. This program 
  demonstrates how to use I/O on the microcontroller itself.
  
  This program uses bit 0 and 1 of port P as input because these
  bits are connected to SW1 and SW2, respectively, on the MCU. Bit 4  
  through 7of port B are used as output because these bits are connected to 
  LED1 through LED4, respectively, on the MCU.

*/
void main(void) {
  
  
  EnableInterrupts;
  
  /*
    NOTE:            
    Writing a 0 to bit y of DDRx sets bit y of Port x to input.
    Writing a 1 to bit y of DDRx sets bit y of Port x to output.
  */

  /* set port B to output */
  DDRB_BIT4 = 1;
  DDRB_BIT5 = 1;
  DDRB_BIT6 = 1;
  DDRB_BIT7 = 1;

  
  /* set port P to input */
  DDRP = 0x00;
  /*enable pullups on pin 0 and 1 of port P*/
  PERP_PERP1 = 1;
  PERP_PERP0 = 1;         
  
  
  
  /* 
    NOTE:
    LEDs on CSM12C128 board are inverted (e.g. putting a 1 or high value
    causes the LED to be off while putting a 0 or low value causes the
    LED to be on.
  */
  
  /* Turn off LED1 and LED2 */
  PORTB = 0xF0;


  /* 
    NOTE:
    Reading a 1 from a bit connected to a SW on the MCU means the button is not
      pressed.
    Reading a 0 from a bit connected to a SW on the MCU means the button is 
      pressed.
  */
  
  /* loop forever */
  for(;;) {
    if(PTP_PTP0 == 0)
      PORTB = 0xE0;
    else if(PTP_PTP1 == 0)
      PORTB = 0xD0; 
    
  } 
  
  /* please make sure that you never leave this function */
}