本人用M16的TC1产生PWM信号，并且在产生信号的同时不断改变频率，但变频幅度很小，这时就出现一个很令人费解的现象，PWM信号会不时有断开的现象

PWM频率：28KHzOC1A、OC1B双路输出：想得到的信号是：
但是一旦改变频率，两路的信号会随即的中断6.5ms左右，不知其解，各位高手请指教
程序：
// Target : M16
// Crystal: 10.000Mhz
#include <iom16v.h>
#include <macros.h>

void port_init(void)
{
PORTA = 0x00;
DDRA  = 0x00;
PORTB = 0x00;
DDRB  = 0x00;
PORTC = 0x00; //m103 output only
DDRC  = 0x00;
PORTD = 0x00;
DDRD  = 0b00110000;
}

//TIMER1 initialize - prescale:1
// WGM: 8) PWM phz freq correct, TOP=ICRn
// desired value: 28KHz
// actual value: 28.090KHz (0.3%)
void timer1_init(void)
{
TCCR1B = 0x00; //stop

TCNT1H = 0xFF; //setup
TCNT1L = 0x4E;

OCR1AH = 0x00;
OCR1AL = 0xB2-0x50;

OCR1BH = 0x00;
OCR1BL = 0x50;

ICR1H  = 0x00;
ICR1L  = 0xB2;

TCCR1A = 0xB0;
TCCR1B = 0x11; //start Timer
}

//call this routine to initialize all peripherals
void init_devices(void)
{
//stop errant interrupts until set up
CLI(); //disable all interrupts
port_init();
timer1_init();

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

void Delay(unsigned int t)
{
   unsigned int i,j;
   
   for(i=0;i<t;i++)
      for(j=0;j<280;j++);

}

void main(void)
{
  unsigned char i;
  unsigned char ICR1L_;

  i=0;
  ICR1L_=0xB2;
  
  SPH=0;
  SPL=220;

  port_init();
  init_devices();
  timer1_init();
  

  while(1)
  {
     i++;
    if(i>9)i=0;
   
    Delay(100); //延时
   
     ICR1L=ICR1L_+i; //改变频率
  
  
  }


}

此帖出自小平头技术问答