at91_timer.c

基于ARM7微控制器AT91X40开发板的定时器程序

/*
 * at91_timer.c
 * 
 * author: Kexin ([e-mail]) Tel:[phone]
 * date:   2007-11-22	
 */
//#include "at91.h"
#include "at91_timer.h"
#include "at91_aic.h"

extern unsigned long svr[32];

int at91_del_timer(unsigned char TimerNum)
{
  register volatile struct at91_timers* tt=(struct at91_timers*)(AT91_TC_BASE);
  register volatile struct at91_timer_channel* tc = &tt->chans[TimerNum].ch;

  if(TimerNum>2)
  	 return -1; 

  at91_mask_irq(TimerNum+4);

  tc->ccr= 0x02;
  tc->rc = 0;

  at91_release_irq(TimerNum+4);
    
  return 1; 	
}

int at91_set_timer(at91_timer_param param)
{
  register volatile struct at91_timers* tt=(struct at91_timers*)(AT91_TC_BASE);
  register volatile struct at91_timer_channel* tc = &tt->chans[param.TimerNum].ch;
  unsigned long v;
  if(param.TimerNum>2 || param.CycleTime==0 || param.irq_svr==0)
  	 return -1; 
  	 
  at91_request_irq(param.TimerNum+4,param.irq_svr);

  tt->bcr=0;
  switch(param.TimerNum)
  {
  	case 0: 
  		v=tt->bmr&0xfc;
  		v|=0x01;
  		break;
  	case 1: 
  		v=tt->bmr&0xf3;
  		v|=0x04;
  		break;
  	case 2: 
  		v=tt->bmr&0xcf;
  		v|=0x10;
  		break; 
  	default:
  		return -1; 		  		
  }
  tt->bmr=v;
  tc->ccr=2;
  tc->cmr=3 | (1<<14);
  tc->idr=~0ul;
  tc->rc=param.CycleTime;
  tc->ier=1<<4;
  tc->ccr=0x05;
  at91_mask_ack_irq(param.TimerNum+4);
  at91_unmask_irq(param.TimerNum+4); 
  return 1; 
}