我有點看不懂你的程式在做什麼? 我幫你將掃瞄鍵盤改成用 Timer 中斷.
你只要判別相對應的 validKey? 做相對應的是就可以了
鍵盤的排列可能跟你要得有點顛倒, 你可以自己改一下 validKey? = validKeyData ^ ?

#include <reg52.h>
#include <intrins.h>

typedef unsigned char BYTE;
typedef unsigned int WORD;

sbit COLUMN1 = P1^0;
sbit COLUMN2 = P1^1;
sbit COLUMN3 = P1^2;
sbit COLUMN4 = P1^3;    
sbit ROW1   = P1^4;
sbit ROW2   = P1^5;
sbit ROW3   = P1^6;
sbit ROW4   = P1^7;

WORD data timerKeyData, pressKeyData, stateKeyData;
WORD bdata validKeyData;
sbit validKey0 = validKeyData ^ 0;
sbit validKey1 = validKeyData ^ 1;
sbit validKey2 = validKeyData ^ 2;
sbit validKey3 = validKeyData ^ 3;
sbit validKey4 = validKeyData ^ 4;
sbit validKey5 = validKeyData ^ 5;
sbit validKey6 = validKeyData ^ 6;
sbit validKey7 = validKeyData ^ 7;
sbit validKey8 = validKeyData ^ 8;
sbit validKey9 = validKeyData ^ 9;
sbit validKeyA = validKeyData ^ 10;
sbit validKeyB = validKeyData ^ 11;
sbit validKeyC = validKeyData ^ 12;
sbit validKeyD = validKeyData ^ 13;
sbit validKeyE = validKeyData ^ 14;
sbit validKeyF = validKeyData ^ 15;

BYTE KeyColNo, KeyColLine;

void Timer0ISR(void) interrupt 1
{
  BYTE key;
  WORD tmp;

  TH0 = 256-120; // (11059200 / 12 / 32) / 120 = 240 Hz
 
  P1 = ~KeyColLine;     // pull high ROWS
  KeyColLine <<= 1;
  KeyColNo++;
  key = ~P1 >> 4;
  timerKeyData = (timerKeyData << 4) | key;
  if (KeyColNo == 4)
  {
    KeyColNo = 0;
    KeyColLine = 0x01;
    tmp = pressKeyData & timerKeyData;
    pressKeyData = timerKeyData;
    validKeyData |= (tmp ^ stateKeyData);
    validKeyData &= pressKeyData;
    stateKeyData = tmp;
  }
}

void main()
{
  TMOD = 0;
  TH0 = 256-120; // (11059200 / 12 / 32) / 120 = 240 Hz
  TR0 = 1;
  ET0 = 1;
  EA = 1;

  KeyColNo = 0x00;
  KeyColLine = 0x01;
  while (1)
  {
    if (_testbit_(validKey0))
      ;
  }
}

我的程式只是單存的跑馬燈~P1 P2 輸出~
4*4鍵盤 控制不同的狀態