C51 COMPILER V7.08   KEYSCAN                                                               05/12/2007 17:30:02 PAGE 1   


C51 COMPILER V7.08, COMPILATION OF MODULE KEYSCAN
OBJECT MODULE PLACED IN keyscan.OBJ
COMPILER INVOKED BY: D:\工具安裝目錄二\Keil C51\C51\BIN\C51.EXE keyscan.c BROWSE DEBUG OBJECTEXTEND

line level    source

   1          #include <reg52.h>
   2          //#include <at89x52.h>
   3          //unsigned char code BCD[]={0x3f,0x06,0x5b,0x4f, //此處是將0-F轉換成相應的BCD碼
   4          //                          0x66,0x6d,0x7d,0x07, 
   5          //                          0x7f,0x6f,0x77,0x7c, 
   6          //                          0x39,0x5e,0x79,0x71};
   7          //unsigned char code KEY[]={0x00,0x00,0x01,0x02,0x03,//此處是為使程序通用,當鍵值不是按
   8          //                                                         0x04,0x05,0x06,0x07,//這個排列時,把此表更改即可
   9          //                                                         0x08,0x09,0x0a,0x0b,//最前面的那個0x00是為了查表方便,
  10          //                                                         0x0c,0x0d,0x0e,0x0f};//因為鍵值是從1開始的
  11                                                                  
  12          sfr key_port=0x90;          //定義P1口為鍵盤掃描口
  13          bit key_ok=0;           //有鍵按下的標志
  14          
  15          /*************延時子程序*************
  16          ****調用一次用時18微秒,t每加1,用時增加6微秒*/
  17          void delay(unsigned char t)
  18          {
  19   1       while(t--);
  20   1      }
  21          
  22          
  23          unsigned char r_left(unsigned char x)//循環左移一位
  24          {
  25   1       x<<=1;
  26   1       x++;
  27   1       return(x);
  28   1      }
  29          
  30          /*************粗判有無鍵按下**********
  31          ****有鍵按下則將key_ok置1************/
  32          void scan_full(void)
  33          {
  34   1              unsigned char temp;
  35   1              key_port=0xf0;          //低半字節為行線,高半字節為列線
  36   1              temp=P1;
  37   1              if(temp!=0xf0)
  38   1              key_ok=1;
  39   1              else key_ok=0;
  40   1      }
  41          /************鍵盤掃描程序*************************
  42          ****功能:返回鍵值,當無鍵按下時,返回0*************/
  43           unsigned char key_scan(void)
  44          {
  45   1       unsigned char temp,count=0x01,key_value;//按鍵返回值
  46   1       unsigned char x_scan=0xfe,y_scan=0xef;//行、列掃描碼
  47   1       unsigned char i,j,y;           //行數和列數
  48   1       while(1)
  49   1       {
  50   2              scan_full();                    //粗判是否有鍵按下
  51   2              if(key_ok==1)
  52   2              {
  53   3                      key_ok=0;
  54   3                      delay(200);                     //延時去抖動
  55   3                      scan_full();                    //再次粗判是否有鍵按下
C51 COMPILER V7.08   KEYSCAN                                                               05/12/2007 17:30:02 PAGE 2   

  56   3                      if(key_ok==1)
  57   3                      {
  58   4                      for(i=0;i<4;i++)                //掃描4行
  59   4                      {
  60   5                                      key_port=x_scan;
  61   5                              for(j=0;j<4;j++)                //每行4列
  62   5                              {
  63   6                                      temp=key_port;
  64   6                                              temp=temp&0xf0;
  65   6                                              y=y_scan&0xf0;
  66   6                                              if(temp==y)
  67   6                                              {
  68   7                                                      while(key_ok!=0)//等待按鍵松開
  69   7                                                      {
  70   8                                                              scan_full();
  71   8                                                      }
  72   7                                                      key_value=count;                                                                                                
  73   7                                                      return(key_value);//找到鍵值,馬上返回
  74   7                                              }
  75   6                                              else 
  76   6                                              {
  77   7                                                      count++;
  78   7                                                      y_scan=r_left(y_scan);
  79   7                                              }        
  80   6                                      }
  81   5                                      y_scan=0xef;            //掃描完一列,重新對列掃描量賦初值
  82   5                                      x_scan=r_left(x_scan);//行掃描碼左移一位,掃描下一行                                     
  83   5                              }
  84   4                      }
  85   3              } 
  86   2          return(key_value);//沒鍵按下,返回0
  87   2       }
  88   1      }
  89          
  90          //unsigned char key(void)
  91          //{
  92           // unsigned char x;
  93           // unsigned char y;
  94           // x=key_scan();
  95           // return(x);
  96            //y=KEY[x];   
  97            //return y;
  98          //}


MODULE INFORMATION:   STATIC OVERLAYABLE
   CODE SIZE        =    114    ----
   CONSTANT SIZE    =   ----    ----
   XDATA SIZE       =   ----    ----
   PDATA SIZE       =   ----    ----
   DATA SIZE        =   ----       1
   IDATA SIZE       =   ----    ----
   BIT SIZE         =      1    ----
END OF MODULE INFORMATION.


C51 COMPILATION COMPLETE.  0 WARNING(S),  0 ERROR(S)