ex2_timer.c

基于摩托罗拉S12标准源程序 包括：SCIO,Timer

/******************************************************************************
*                                                  
*  (c) copyright Freescale Semiconductor Hong Kong Ltd. 2004
*  ALL RIGHTS RESERVED
*                                                                       
*******************************************************************************  
** THIS  CODE IS ONLY INTENDED AS AN EXAMPLE FOR DEMONSTRATING THE FREESCALE **
** MICROCONTROLLERS.  IT  HAS ONLY BEEN GIVEN A MIMIMUM LEVEL OF TEST. IT IS **
** PROVIDED  'AS  SEEN'  WITH  NO  GUARANTEES  AND  NO  PROMISE  OF SUPPORT. **
*******************************************************************************  
*                                                                           
* FILE:         ex2_timer.c	          REVISION 0.2
*  
* DESCRIPTION:  Application code is placed here.
*               This module handles all tasks related to the internal timer
*               Program to control the timer periodic interrupt 
*
* TARGET DEVICE: 		Hardware EVB912DP256 or equivalent                                                                                                                                                      
*
* COMPILER: Metrowerks            VERSION: ADS v1.2 (initial version)           
*                                 VERSION: ADS v2.0 (Demo beta version)
*                                 VERSION: ADS v3.1 (Demo version)
*																												 
* NOTES
* -----
* All modules remain at their reset addresses.                                                      
*
*
* UPDATED HISTORY:
*
* REV   YYYY.MM.DD  AUTHOR        DESCRIPTION OF CHANGE
* ---   ----------  ------        --------------------- 
* 0.0   2002.04.20  Kenny Lam     Initial version
* 0.1   2002.07.12  Kenny Lam     Demo beta version
* 0.2   2004.04.12  Kenny Lam     Demo version
*
******************************************************************************/                                                                        
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#include <hidef.h>
#include "const.h"
#include "DP256Port.h"
#include "GlobalVar.h"
          
#ifdef BANKED
#pragma CODE_SEG CodeForcedToPPage33								 
#else
#pragma CODE_SEG DEFAULT
#endif

/**********************************************
* Timer initilaisation subroutine
***********************************************/
void init_timer()
{
    TIE = 0x80;				//Enable ch7 timer  
        						
    TIOS = 0x80; 			//Select Channel 7 to act as output compare.  80
    TC7W = MS80; 			//updated 8msec with 8Mhz bus clk
    TSCR1 = 0xb0;			//Enable timer, Timer Module Stops While in Wait
	  COPCTL =0;
	 
}

/**********************************************
* Timer interrupt service subroutine
* - Perform timer data update by 1 sec with 
*   bus clk = 8Mhz
***********************************************/
#pragma CODE_SEG NON_BANKED
#pragma TRAP_PROC
void Timer7Overflow_ISR(void)
{
  	TC7W += MS80;		  //updated 8msec with 8Mhz bus clk
	Time8ms++; 
    if (TimerCounter++ >=125)
	{
	  PORTB ^=2;    	  //toggle output port to drive LED 1 sec on/off
	  TimerCounter=0;	  //reset timer_counter
	  SecData++;		    //update second variable
	  if(SecData>=60)
	  {
	  	SecData=0;		  //clear second variable
	  	MinData++;	  	//update miniute variable
	  }
	  if(MinData>=60)
	  {
	    MinData=0;		  //clear miniute variable
	    HourData++;		  //update hour variable
	  }
	  if(HourData>=24)
	  	HourData=0;		  //clear hour variable
	}	

}