XS128输出比较(OC)的简单例子

librae8226 · 发表于 2009-11-13 20:01:13

今天一下午测试XS128的定时器模块，包括IOC和PIT，感觉飞思这个系列的定时器做得用起来有些不方便，Reference Manuel里说得也不是太清楚，尤其是输出比较的用法，在论坛里逛了一大圈也没明白……后来调通了这里贴出我的代码供初学者参考。

#include <hidef.h>    /* common defines and macros */
#include <MC9S12XS128.h>    /* derivative information */

#pragma LINK_INFO DERIVATIVE "mc9s12xs128"

#pragma CODE_SEG __NEAR_SEG NON_BANKED

unsigned int counter;

void interrupt 8 Compare_ISR(void)
{
  if( counter == 50000 ) //Although enormous,PORTB flashes very fast at 16MHz
  {
PORTB = ~PORTB; // Toggle PORTB Every 50000 times
counter = 0;
  }
  counter += 1;
  TFLG1 = 0x01; // Clear T0 interrupt flag
}

void SetBusCLK(void) /* 16MHz */
{
  CLKSEL = 0x00; /* disengage PLL to system */
  PLLCTL_PLLON = 1; /* turn on PLL */
  SYNR = 0x01;
  REFDV = 0x81;
  POSTDIV = 0x00;
  _asm(nop); /* BUS CLOCK=80M */
  _asm(nop);
  while( !(CRGFLG_LOCK == 1) ); /* when pll is steady ,then use it */
  CLKSEL_PLLSEL =1; /* engage PLL to system */
}

void OutputCompare_Init(void)
{
  TIE = 0x00; /* Disable all channel interrupt */
  TIOS = 0x01; /* channel 0 set to Output Compare */
  TSCR1 = 0x90; /* Enable Timer; */
                     /* Timer interrupt flag can be cleared(channel 0) */
  TSCR2 = 0x07; /* Prescale Factor = 128 */
  TC0 = 0xFF00;
  TIE = 0x01; /* Enable channel 0 interrupt */
}

void Port_Init(void)
{
  DDRB = 0xFF;
  PORTB = 0xFF;
}

void main(void)
{
  /* put your own code here */

  DisableInterrupts;

  SetBusCLK();
  Port_Init();
  OutputCompare_Init();

  counter = 0;

  EnableInterrupts;

  for(;;)
  {
_FEED_COP();
  }
  /* wait forever */
  /* please make sure that you never leave this function */
}