请教高手如何使用attiny231３的Ｔ１比较匹配功能

只看该作者 · 2007-5-6 15:35

定时器Ｔ１使用了捕获功能，同时还要使用Ｔ１Ａ比较匹配功能，在ＰＢ３输出波形．捕获发生时清ＴＩＣＯＵＮＴ计数器，同时希望ＰＢ３输出低电平，当Ｔ１ＣＯＵＮＴ与ＯＣＲ１Ａ相等时比较匹配，ＰＢ３输出高电平．请问该如何操作比较匹配输出单元？

只看该作者 · 2007-5-6 20:23

教程是基于ICC的，mega16的程序。

http://www.avrvi.com/avr_examples/pwm.html

相关链接:http://www.avrvi.com

只看该作者 · 2007-5-6 22:10

谢谢AVRVI先生的回帖.我的意图不是做PWM输出,而是而是对一个信号捕捉,然后再准确的延时一个固定时间.原程序如下,错在哪里?
//ICC-AVR application builder : 2007-5-2 12:56:18
// Target : T2313
// Crystal: 3.93216Mhz

#include <iot2313v.h>
#include <macros.h>

unsigned char flag=1,il,ih;

#pragma interrupt_handler timer1_capt_isr:4
void timer1_capt_isr(void)
{
  //TCCR1B = 0x00; //stop timer
TCNT1H = 0x00; //set count value
TCNT1L = 0x00;//analog comparator compare event
  TCCR1C=0X80;
  NOP();
  TCCR1C=0X00;
  TCCR1A=0xc0;
if(flag)
   {
   il=ICR1L;
   ih=ICR1H;
   flag=0;
   }
}

#pragma interrupt_handler timer1_compa_isr:5
void timer1_compa_isr(void)
{
TCCR1A = 0x80;
}

#pragma interrupt_handler timer1_ovf_isr:6
void timer1_ovf_isr(void)
{
;
}

void main(void)
{
//stop errant interrupts until set up
CLI(); //disable all interrupts

PORTA = 0x00;
DDRA  = 0x00;
PORTD = 0x00;
DDRD  = 0x00;
PORTB = 0x00;
DDRB  = 0x1c;
//UART0 initialize
// desired baud rate: 9600
// actual: baud rate:9600 (0.0%)

UCSRB = 0x00; //disable while setting baud rate
UCSRC = 0x06;
UBRRH = 0x00; //set baud rate upper
UBRRL = 0x19; //set baud rate lower
UCSRA = 0x00;
UCSRB = 0x18; //enable
//Comparator initialize
// trigger on: Rising output edge

ACSR = 0x06; //下降沿触发、捕获

//TIMER1 initialize - prescale:1
// WGM: 0) Normal, TOP=0xFFFF
// desired value: 550uSec
// actual value: 549.825uSec (0.0%)
TCCR1B = 0x00; //stop timer
TCNT1H = 0x00; //set count value
TCNT1L = 0x00; //set count value
OCR1AH  = 0x08; //set compare value
OCR1AL  = 0x72;
TCCR1A = 0xc0;
TCCR1B = 0x01; //start Timer

MCUCR = 0x00;
GIMSK = 0x00;
TIMSK = 0xC8;
SEI(); //re-enable interrupts
//all peripherals are now initialized

while(1)
{
while(!flag)
{
UDR = ih;
while(!(UCSRA&0x20));
  UCSRA |= 0x20;
  UDR = il;
  while(!(UCSRA&0x20));
  UCSRA |= 0x20;
  UDR = 0x0d ;
   while(!(UCSRA&0x20));
  UCSRA |= 0x20;
  UDR = 0x0a ;
   while(!(UCSRA&0x20));
  UCSRA |= 0x20;
  //UCSRB = 0x0C; //enable
  flag=1;
  }
}
}