timer.c

使用8880实现DTMF通信及拨号的程序.

#include <iom8v.h>
#include "main.h"
#include "shell.h"
#include "8880.h"
#include "serial.h"
void timer1_init(void)
{
 TCCR1B = 0x00; //stop
 TCNT1H = 0xE3; //setup
 TCNT1L = 0xE1;
 OCR1AH = 0x1C;
 OCR1AL = 0x1F;
 OCR1BH = 0x1C;
 OCR1BL = 0x1F;
 ICR1H  = 0x1C;
 ICR1L  = 0x1F;
 TCCR1A = 0x00;
 TIMSK |= 0x04;
}

int x=0;
#pragma interrupt_handler timer1_ovf_isr:iv_TIM1_OVF
void timer1_ovf_isr(void)
{
 int i;
 //TIMER1 has overflowed
 TCNT1H = 0xE3; //reload counter high value
 TCNT1L = 0xE1; //reload counter low value
 switch (sysoption.calling)
 {		case 1:
 			 if (sysoption.timer==40){
			   	M8880_Handdown;
				for (i=0;i<10;i++) delay(0xffff);
 				serial_send(noresponse);
				sysoption.calling=0;
				TCCR1B=0x0;
			 }else	 sysoption.timer++;
			 break;
		case 2:
			   	sysoption.calling=3;
				serial_send("answered");
				TCCR1B=0;
				break;
 }
}