PIT代码

PIT代码#include/*commondefinesandmacros*/#include/*derivativeinformation*/#pragmaLINK_INFODERIVATIVE"mc9s12xs128"//==================================================//定时中断函数//定时中断0实现500MS定时//author:yangtze//time:2009/5/2//==================================================#definePITTIME5000//设定为50MS定时unsignedintvTmpPIT=0;voidpllclk(void)//24MHz，外部时钟为16MHz{CLKSEL=0X00;PLLCTL=0xe1;SYNR=2;//PLLCLK=2*OSCCLK*(SYNR+1)/(REFDV+1)REFDV=1;PLLCTL=0X60;asmNOP;asmNOP;asmNOP;while((CRGFLG&0X08)==0);//时钟校正同步CLKSEL=0X80;}voidinitIOBoutput(void)//IO口初始化，B口为输出{DDRB=0XFF;PORTB=0XFF;}voidinitPIT(void)//