keyscan_1.h

本代码详细说明了

#include <SubStruct.h>

static unsigned char Keyscan(void) large
{
  unsigned char i, bKeyData;
  bKeyData = 0;
  DATA=1; 
  for(i = 0; i < 8; i++)
  {
    CLK=1;
    //bKeyData <<= 1;
    CLK=0;
    Delay(0);
    /* delay for data output ready */
  //  _nop_(); _nop_(); _nop_();

    if (DATA)
    {
      bKeyData |= (1 << i);
    }
  }

  return (bKeyData);
}