oc1ab输出pwm._c

ICC mega8例子

//ICC-AVR application builder : 2009-3-11 13:52:41
// Target : M8
// Crystal: 8.0000Mhz

#include <iom8v.h>
#include <macros.h>

void port_init(void)
{
 PORTB = 0x00;
 DDRB  = 0x00;
 PORTC = 0x00; //m103 output only
 DDRC  = 0x00;
 PORTD = 0x00;
 DDRD  = 0x00;
}

//call this routine to initialize all peripherals
void init_devices(void)
{
 //stop errant interrupts until set up
 CLI(); //disable all interrupts
 port_init();

 MCUCR = 0x00;
 GICR  = 0x00;
 TIMSK = 0x00; //timer interrupt sources
 SEI(); //re-enable interrupts
 //all peripherals are now initialized
}

/************************************
用    途:用TC1输出PWM
Taget   :mega8
crystal :8M
介    绍:PB1(OC1A),PB2(OC1B)
入口参数:A,B的占空比
出口参数:
*************************************/
void init_timer1_PWM(unsigned int x,unsigned int y)
{
 DDRB|=(1<<PB1)|(1<<PB2);
 TCCR1B=0x0;//先停止TC1
 TCNT1=0;//设置TCNT1的初值
 OCR1A=x;//设置OC1A的初值
 OCR1B=y;//设置OC1B的初值
 ICR1=0xff;//设置ICR的初值
 //系统时钟64分频CS1[2、0]=0x03
 //COM1A[1-0]=0x00,COM1B[1-0]=0x02
 TCCR1A|=(1<<COM1A1)|(1<<COM1B1)|(1<<WGM11);
 TCCR1B|=(1<<WGM13)|(1<<CS11)|(1<<CS10);//Starttimer
}
void timer1_PWM(unsigned int x,unsigned int y)
{
 OCR1A=x;
 OCR1B=y;
}

void main()
{
 port_init();
 init_devices();
 
 init_timer1_PWM(100,200);
 while(1)
 {
  PORTB=0xff;
 }
}