各位大哥：我在练习MC9S12XEP芯片，但是我在做中断程序的时候，始终不能正确的运行到中断处理程序，一中断就跑飞了，好像。那位大哥给指点一下阿。谢谢啦！附上程序：

void main(void) {
/* put your own code here */
int i=1000;
IVBR = 0xff; /* interrupt vector base address at $ff00 */
S12X_SetInterruptPriority(0x47,RQST + 0x07);

DDRA=0xFF; //选择输入输出方向
DDRP=0x00;
PIEP=0xff; //选择打开PP0中断
PIFP=0x00; //清中断标志
SetupXGATE();
EnableInterrupts;

for(;;) {
PORTA_PA3=1;
for(i=20000;i>=0;i--){ }
PORTA_PA3=0;
for(i=20000;i>=0;i--){ }
} /* wait forever */
/* please make sure that you never leave this function */
}
//# pragma CODE_SEG DEFAULT

#pragma NO_FRAME
#pragma NO_ENTRY
#pragma NO_EXIT

#pragma CODE_SEG __NEAR_SEG NON_BANKED /* make sure this code is located in non banked */

interrupt 47 void ISR(void){
PIEP=0x00;//停中断
PIFP=0x00; //清中断标志
PORTA_PA2=!PORTA_PA2;
PIEP=0xff;//开中断
}