// 硬件實驗十六  八段數碼管顯示

#define LEDLen 6

xdata unsigned char OUTBIT _at_ 0x8002;   // 位控制口
xdata unsigned char OUTSEG _at_ 0x8004;   // 段控制口
xdata unsigned char IN     _at_ 0x8001;   // 鍵盤讀入口

unsigned char LEDBuf[LEDLen];  // 顯示緩沖
code unsigned char LEDMAP[] = {  // 八段管顯示碼
  0x3f, 0x06, 0x5b, 0x4f, 0x66, 0x6d, 0x7d, 0x07,
  0x7f, 0x6f, 0x77, 0x7c, 0x39, 0x5e, 0x79, 0x71
};

void Delay(unsigned char CNT)
{
  unsigned char i;

  while (CNT-- !=0)
    for (i=100; i !=0; i--);
}

void DisplayLED()
{
  unsigned char i, j;
  unsigned char Pos;
  unsigned char LED;

  Pos = 0x20;      // 從左邊開始顯示
  for (i = 0; i < LEDLen; i++) {
    OUTBIT = 0;    // 關所有八段管
    LED = LEDBuf[i];
    OUTSEG = LED;
    OUTBIT = Pos;  // 顯示一位八段管
    Delay(1);
    Pos >>= 1;     // 顯示下一位
  }
  OUTBIT = 0;      // 關所有八段管
}

void main()
{
   unsigned char i = 0;
   unsigned char j;

   while(1) {
     LEDBuf[0] = LEDMAP[ i    & 0x0f];
     LEDBuf[1] = LEDMAP[(i+1) & 0x0f];
     LEDBuf[2] = LEDMAP[(i+2) & 0x0f];
     LEDBuf[3] = LEDMAP[(i+3) & 0x0f];
     LEDBuf[4] = LEDMAP[(i+4) & 0x0f];
     LEDBuf[5] = LEDMAP[(i+5) & 0x0f];

     i++;

     for(j=0; j<30; j++)
       DisplayLED();   // 延時
   }
}