#ifndef REG52
  #include <reg52.h>
#endif

#ifndef SUBSTRUCT
  #include <SubStruct.h>
#endif

#define KEYSCAN 0x42

bit EJECT,PLPS,NEXT,PRE;
/*
void nop()
{
 unsigned char i;
 i=0;
 for(i=0;i<4;i++)
{}
}
*/

unsigned char keyscan()
{
 unsigned char i;
 unsigned char key=0;
 
 
 SendCommand(KEYSCAN);
 DATA=1;
 Delay(1);

  for (i=0;i<8;i++)
  {
   CLK=1;
   if (DATA)
   {
    Delay(10);   // nop();
    if (DATA)
    {
     Delay(10);//nop();
     if (DATA) {key|=(0x01<<i);}
     }
    }
   CLK=0;
  Delay(10);// nop();
  }
  
  SendCommand(DATA_SET);
// SendAddress(Seg_B);
//  SendData(key);

  Delay(200);
 
 return key;
} 


void Display_Key(unsigned char key)
{
 switch(key)
 {
  case 0x03:
      if (EJECT)
      {
        EJECT=0;
        ClearLocation(Seg_A,6);
        Delay(10);
        Display_Flag('P');
        Delay(10);
      }     
      else
      {
    //   ClearDisMemo();
       ClearLocation(Seg_A,6);
       ClearLocation(Seg_B,6);
       ClearLocation(Seg_C,6);
       ClearLocation(Seg_D,6);
       ClearLocation(Seg_E,6);
       ClearLocation(Seg_F,6);
       ClearLocation(Seg_A,7);
       ClearLocation(Seg_B,7);
       ClearLocation(Seg_D,7);
       ClearLocation(Seg_E,7);
       Delay(10);
       EJECT=1;
       PLPS=0;
       PRE=0;
       NEXT=0;
       Display_Flag('T');
       Delay(10);
      }
       
      break;
  case 0x11:
      if (PLPS) 
      {  
       PLPS=0;
       Display_Flag('P');
       EJECT=0;
       PRE=0;
       NEXT=0;
       ClearLocation(Seg_D,6);
       Delay(10);
       
      }
      else
      {
       PLPS=1;
       Display_Flag('S');
       ClearLocation(Seg_C,6);
       Delay(10);
      }
      break;
  case 0x21:
      if (PRE) 
      {
      ClearLocation(Seg_A,7);
      Delay(10);
      }
      Display_Flag('B');
      Delay(10);
      ClearLocation(Seg_C,6);
      Delay(10);
      ClearLocation(Seg_D,6);
      Delay(10);
      PLPS=1;
      PRE=0;
      NEXT=1;
      break;
  case 0x41:
      if (NEXT)
      { 
      ClearLocation(Seg_B,7);
      Delay(10);
      }
      Display_Flag('M');
      Delay(10);
      ClearLocation(Seg_C,6);
      Delay(10);
      ClearLocation(Seg_D,6);
      Delay(10);
      PLPS=1;
      NEXT=0;
      PRE=1;
      break;
  }
}