//“模仿式”實驗三   雙機通訊實驗
#include <reg51.h>
#define LEDLen 6
#define MODE 0x03
xdata unsigned char CAddr  _at_ 0xe100;   // 命令控制口
xdata unsigned char OUTBIT _at_ 0xe101;   // 位控制口
xdata unsigned char CLK164 _at_ 0xe102;   // 段控制口(接164時鐘位)
xdata unsigned char DAT164 _at_ 0xe102;   // 段控制口(接164數據位)
xdata unsigned char IN     _at_ 0xe103;   // 鍵盤讀入口

unsigned char LEDBuf[LEDLen];  // 顯示緩沖
unsigned char RcvBuf;          // 接收緩沖
bit HasRcv = 0;                // 接收標志

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 SerialIO0() interrupt 4
{

  if(RI)
  {
    RI = 0;
    RcvBuf = SBUF;
    HasRcv = 1;
  }else
  {
    TI = 0;
  }
}

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;
  CAddr= MODE;
  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];
    for (j = 0; j < 8; j++) {   // 送164
      if (LED & 0x80) DAT164 = 1; else DAT164 = 0;
      CLK164 = CLK164 | 0X02;
      CLK164 = CLK164 & 0Xfd;
      LED <<= 1;
    }
    OUTBIT = Pos;  // 顯示一位八段管
    Delay(1);
    Pos >>= 1;     // 顯示下一位
  }
}

code unsigned char KeyTable[] = {   // 鍵碼定義
  0X00, 0X01, 0X04, 0X07,
   0X0f, 0X02, 0X05, 0X08,
   0X0e, 0X03, 0X06, 0X09,
   0X0d, 0X0c, 0X0b, 0X0a,
   0X10, 0X10, 0X10, 0X10,
   0X10, 0X10, 0X10, 0X10,
};

unsigned char TestKey()
{
   OUTBIT = 0;            // 輸出線置為0
   return (~IN & 0x0f);   // 讀入鍵狀態 (高四位不用)
}

unsigned char GetKey()
{
  unsigned char Pos;
  unsigned char i;
  //unsigned char j;
  unsigned char k;

  i = 6;
  Pos = 0x20;     // 找出鍵所在列
  do {
    OUTBIT = ~ Pos;
    Pos >>= 1;
    k = ~IN & 0x0f;
  } while ((--i != 0) && (k == 0));

  // 鍵值 = 列 X 4 + 行
  if (k != 0) {
    i *= 4;
    if (k & 2)
      i += 1;
    else if (k & 4)
      i += 2;
    else if (k & 8)
      i += 3;

    OUTBIT = 0;
    do Delay(10); while (TestKey());  // 等鍵釋放

    return(KeyTable[i]);  // 取出鍵碼
  } else return(0xff);
}

void main()
{

    IE =   0x00;  // DISABLE ALL INTERRUPT
    TMOD = 0x20;  // 定時器1工作于方式2 (8位重裝)
    TH1  = 0xF3;  // 2400BPS @ 12MHz
    TL1  = 0xF3;
    PCON = 0x7F;  // SMOD 位清零
    SCON = 0x50;  // 串行口工作方式設置


   LEDBuf[0] = 0xff;
   LEDBuf[1] = 0xff;
   LEDBuf[2] = 0xff;
   LEDBuf[3] = 0xff;
   LEDBuf[4] = 0x00;
   LEDBuf[5] = 0x00;

   TR1 = 1;
   ES  = 1;
   EA  = 1;
   HasRcv = 0;

   while (1) {
     if(HasRcv){
       LEDBuf[5] = LEDMAP[RcvBuf & 0x0f];
     }
     DisplayLED();
     if (TestKey()) SBUF = GetKey();
   }
}