代码如下，各位大虾给看看，用示波器测试PWM0口没有反映，到底怎么回事

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

#pragma LINK_INFO DERIVATIVE "mc9s12dg128b"

#define PWCLK_   (*((volatile unsigned char*)(0x0040)))
#define PWPOL_   (*((volatile unsigned char*)(0x0041)))
#define PWEN_    (*((volatile unsigned char*)(0x0042)))
#define PWSCAL0_ (*((volatile unsigned char*)(0x0044)))
#define PWCNT0_  (*((volatile unsigned char*)(0x0048)))
#define PWPER0_  (*((volatile unsigned char*)(0x004c)))
#define PWDTY0_  (*((volatile unsigned char*)(0x0050)))
#define PWCTL_   (*((volatile unsigned char*)(0x0054)))
#define PORTP_   (*((volatile unsigned char*)(0x0056)))

void main(void) {
  /* put your own code here */
  EnableInterrupts;
 
     PWCLK_   = 0x18;  //通道分用A口32分频
     PWPOL_   = 0x11;   //用s0口做0通道的时钟 先高电平
     PWSCAL0_ = 4;     //s0口提供10kHz的频率                        
   PWPER0_  = 99;    //舵机的频率是100Hz
   PWCNT0_  = 100;
   DDRP     = 0xff;  //控制输出，此行有没有都结果
    PWDTY0_ = 49;
    PWEN_   = 0x01;

  for(;;) {} /* wait forever */
}