pwm.c

网上得到FREESCALE 9S12程序

#include <hidef.h>      /* common defines and macros */
#include <mc9s12dg128.h>     /* derivative information */

//PWM2,PWM3控制电机0与电机1,PB0,PB1分别控制其方向

void PWM_Init(void) {
  //PWME     =  PWME   & 0XFC;    //PWM0,PWM1 disable
  PWMPOL   =  PWMPOL | 0x0C;	  //极性选择
  PWMCLK   =  PWMCLK | 0x0C;		//use SB
  //PWMPRCLK =  0x4;            //clock B 0分频
  PWMSCLB  =  120;				  		//240分频  (SA) 0.1MHz,10uS
  
  //PWMCAE   =  PWMCAE & 0XFC;   //计数方式,0 to counter.
  //PWMCTL   =  0;               //8-bit
  PWMPER2  =  250;							 //2.5ms
  PWMPER3  =  250;
  PWMDTY2  =  125;       				 //1.25ms
  PWMDTY3  =  25; 
}