main.c

是网上找到的FREESCALE单片机程序

#include <hidef.h>      /* common defines and macros */
#include <mc9s12dg128.h>     /* derivative information */
#pragma LINK_INFO DERIVATIVE "mc9s12dg128b"

unsigned int speed_m;

/*  16位脉冲累加,5ms测一次,输入PT7*/


void PaiInit();
void RealTimer_Int(void);
void PLL_Init(void);
void Start_PLL(void);


void PaiInit()
{
	TCTL4 = 0X03;
	PACTL_PAEN=1; //PBEN=1,事件技术模式,上升沿触发,PACLK 允许中断
//	ICPAR = 0X0F;
	PACN32 = 0X00;
}


void interrupt 7 RealTime(void)
{
	CRGFLG_RTIF=1;  //Clear Flag
//	PTH^=0X01;
	speed_m = PACN32 ; 
	PACN32=0;		//PT7 采集
}

void RealTimer_Int(void)
{
	CRGINT_RTIE=1;       //Open Interrupt
	RTICTL=0x49;         //5ms Interrupt
}

void PLL_Init(void)
{
	REFDV=0x01; 
	SYNR=0x02;						    //Set the system clock 48MHz
}

void Start_PLL(void) {
  asm{
    BRCLR CRGFLG,#$08,*
    BSET CLKSEL,#$80
    }													  
}

void main(void) {
  /* put your own code here */
  
  DisableInterrupts;
  DDRH=0XFF;
  PLL_Init();
  Start_PLL();
  
  PaiInit();
RealTimer_Int();
  EnableInterrupts;
  for(;;) {} /* wait forever */
  /* please make sure that you never leave this function */
}