PWM不知道什么原因求指教

梁小龙 · 发表于 2013-3-5 16:51:27

#include <hidef.h>    /* common defines and macros */
#include "derivative.h"    /* derivative-specific definitions */
#pragma LINK_INFO DERIVATIVE "mc9s12xs128"

void SetSysCLK_32M (void);
void initPWM(void) ;

void Pwm_init(void);

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

   SetSysCLK_32M;
   initPWM() ;
   EnableInterrupts;

  for(;;)
  {

      // PWMDTY45=2200;
      //  PWMDTY01=100;
      //  PWMDTY23=100;

_FEED_COP(); /* feeds the dog */
  } /* loop forever */
  /* please make sure that you never leave main */
}

void Pwm_init(void)
{
PWMPRCLK=0x22;
PWMSCLA=4;
PWMSCLB=4;
PWMCTL_CON45=1;
PWMCTL_CON23=1;
PWMCTL_CON01=1;
PWMCLK_PCLK1=1;
   PWMCLK_PCLK3=1;
      PWMCLK_PCLK5=1;
      PWMPER45=10000;
      PWMPER01=200;
      PWMPER23=200;
      PWMPOL_PPOL5=1;
      PWMPOL_PPOL1=0;
      PWMPOL_PPOL3=0;
      PWMCAE=0x00;
      PWME_PWME5=1;
      PWME_PWME3=1;
      PWME_PWME1=1;
}

void initPWM()
{
PWME=0x00;             //禁止PWM

PWMCTL=0x20;          //23级联,其他都不联级

PWMCLK=0xFF;          //选择的PWM时钟源为ClockSA、ClockSB

PWMPRCLK=0x22;       //ClockB预分频4,ClockA分频4

PWMSCLA=2;          //ClockSA预分频4对ClockA的4分频在

PWMSCLB=2;             //ClockSB预分频4对ClockB的4分频在

PWMCAE=0;             //所有的通道左对齐

PWMPOL=0xFF;          //所有PWM一开始输出高电平
PWMPER23=40000;       //重点计算的 PWM23周期  32M/(4*4)=2M  1/(2M)*40000=20ms

PWMDTY23=3016;          //占空比///高电平的时间
PWMPER5=250;             //PWM5周期

PWMDTY5=100;             //PWMDTY5大小与反向转速成正比

PWMPER4=250;             //PWM4周期

PWMDTY4=100;             //PWMDTY4大小与正向转速成正比
PWME_PWME4=1;             //允许PWM输出
PWME_PWME5=1;             //允许PWM输出
PWME_PWME3=1;             //允许PWM输出

}

void SetSysCLK_32M (void)
{
CLKSEL = 0X00; // disengage PLL to system
PLLCTL_PLLON = 1; // turn on PLL
SYNR = 0x40|0x03;  // pllclock=2*osc*(1+SYNR)/(1+REFDV)=64MHz;
REFDV = 0x80|0x01;
POSTDIV = 0x00;
_asm (nop);       // BUS CLOCK=32M
_asm (nop);
while (!(CRGFLG_LOCK == 1)); // when pll is steady ,then use it;
CLKSEL_PLLSEL = 1;       // engage PLL to system;
}