圣龙扬特-AVR电子

标题: ICCAVR的6路PWM输出实验 [打印本页]

作者: 铜河 时间: 2013-2-28 20:05
标题: ICCAVR的6路PWM输出实验
//ICC-AVR application builder : 2008-7-12 20:25:58
// Target : M16
// Crystal: 7.3728Mhz

#include <iom16v.h>
#include <macros.h>

unsigned char m; //定义全局变量

void port_init(void)
{
PORTA = 0xFF;
DDRA  = 0x00;
PORTB = 0x00;
DDRB  = 0xFF;
}

//TIMER1 initialize - prescale:64
// WGM: 0) Normal, TOP=0xFFFF
// desired value: 2Hz
// actual value:  2.000Hz (0.0%)
void timer1_init(void)
{
TCCR1B = 0x00;
TCNT1H = 0x1F;
TCNT1L = 0x01;
TCCR1A = 0x00;
TCCR1B = 0x03;
}

#pragma interrupt_handler timer1_compa_isr:7
void timer1_compa_isr(void)
{
PORTB = 0x00; //清端口
}

#pragma interrupt_handler timer1_ovf_isr:9
void timer1_ovf_isr(void)
{
TCNT1H = 0x1F;
TCNT1L = 0x01;
m++;
if(m>=6)m=0;
PORTB |= 1<<m; //各端口置1
}

//call this routine to initialize all peripherals
void init_devices(void)
{
CLI();
port_init();
timer1_init();

MCUCR = 0x00;
GICR  = 0x00;
TIMSK = 0x14; //允许溢出中断和匹配中断
SEI();
}

void main(void)
{
init_devices();
OCR1A = 20000; //比较匹配值，此值决定脉冲宽度

while(1);
}

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