#include <hidef.h> /* for EnableInterrupts macro */
#include <MC68HC908SR12.h> /* include peripheral declarations */

void main(void) {
 
  CONFIG1 = 0x39;
  DDRD =  0xF0;     //PTD高四位作為輸出，低四位作為輸入
  PTD &= 0x0F;      //PTD高四位輸出初始值為0
  KBSCR_MODEK = 1;  //選擇觸發方式為下降沿和低電平
   /*Initialize KeyBoard(to prevent a false interrupt)*/
  KBSCR_IMASKK = 1;
  KBIER = 0x0F;     
  KBSCR_ACKK = 1;
  KBSCR_IMASKK = 0;  
  EnableInterrupts; /* enable interrupts */
  for(;;);
}

interrupt  void  KBI_ISR(void)
{
    KBSCR_IMASKK = 1;  //屏蔽鍵盤中斷
    if(PTD_PTD0==0)    //在中斷服務程序中查詢是由哪一個口引起的中斷 
    {
      PTD=0;
      PTD_PTD4 = 1;    //點亮指示試驗板指示燈用作驗證
    }
    if(PTD_PTD1==0) 
    {
      PTD=0;
      PTD_PTD5 = 1;
    }
	KBSCR_ACKK = 1;   //清除中斷確認，避免誤中斷
	KBSCR_IMASKK = 0; //不屏蔽鍵盤中斷
}