/*************************************************
*						*
*     Program:	Port H Switch Inputs		*
*						*
*     Name   :	phoa4evb.c			*
*						*
*     Date   :	13 June 2002			*
*						*
*     By     :	Jake Gamage      		*
*		Adapted from phoa4evb.asm	*
*		written by Steven J. Dombrowski	*
*                                               *
*     This program outputs all 8 bits on	*
* the M68HC12A4EVB and continuously updates all	*
* outputs.					*
*						*
*     To execute this program type G 5000 <CR>	*
*						*
************************************************/


#include <hc812a4.h>
#include <introl.h>
#include <dbug12.h>

/* D_1MS is the time it takes for the processor to execute one
   subtract operation.  It is used to somewhat accurately create a delay.
   The compiler adds a lot of overhead, so its hard to tell exactly how
   long the delay function actually takes.  For a more accurate timer 
   setup, try using the timed interrupts to keep track. */

/* I could define this as (800/2) for the frequency divided by the clock
   cycles for a subtract instruction.  However, every time D_1MS would 
   appear in the code, it would have to perform a divide instruction (this
   is very slow compared to other instructions). */
#define D_1MS 400

void delay(unsigned int);

int __main()
{
  _H12DDRH = 0xFF; /* Set for all output */
  DB12->printf("This program will output all 8 bits on PortH\n\r");
  while(1)
    {
      /* This program just outputs a different value to Port H 
	 every half second.  This will make the signals on Port H 
	 flash in sequence. */

      _H12PORTH = 0xFE;
      delay(500);
      _H12PORTH = 0xFD;
      delay(500);
      _H12PORTH = 0xFB;
      delay(500);
      _H12PORTH = 0xF7;
      delay(500);
      _H12PORTH = 0xEF;
      delay(500);
      _H12PORTH = 0xDF;
      delay(500);
      _H12PORTH = 0xBF;
      delay(500);
      _H12PORTH = 0x7F;
      delay(500);
    }

}

void delay(unsigned int ms)
{
  int i;
  int j = D_1MS;
  while(ms > 0)
    {
      i = j;
      while(i > 0)
	{
	  i-=1;
	}ms-=1;
    }
}