#include <reg52.h>
sbit ADDR0 = P1^0;
sbit ADDR1 = P1^1;
sbit ADDR2 = P1^2;
sbit ADDR3 = P1^3;
sbit ENLED = P1^4;
sbit KEY1 = P2^4;
sbit KEY2 = P2^5;
sbit KEY3 = P2^6;
sbit KEY4 = P2^7;
unsigned char code LedChar[] = { //數碼管顯示字符轉換表
0x3f, 0x06, 0x5b, 0x4f, 0x66, 0x6d, 0x7d, 0x07,
0x7f, 0x6f, 0x77, 0x7c, 0x39, 0x5e, 0x79, 0x71
};
void delay();
void main()
{
bit keybuf = 1; //按鍵值暫存，臨時保存按鍵的掃描值
bit backup = 1; //按鍵值備份，保存前一次的掃描值
unsigned char cnt = 0; //按鍵計數，記錄按鍵按下的次數
ADDR3 = 1;
ADDR2 = 0;
ADDR1 = 0;
ADDR0 = 0;
P2 = 0xf7; //P2.3置0，即KeyOut1輸出低電平
P0 = LedChar[cnt]; //顯示按鍵次數初值
while (1)
{
keybuf = KEY4; //把當前掃描值暫存
if (keybuf != backup) //當前值與前次值不相等說明此時按鍵有動作
{
delay(); //延時大約10ms
if (keybuf == KEY4) //判斷掃描值有沒有發生改變，即按鍵抖動
{
if (backup == 0) //如果前次值為0，則說明當前是彈起動作
{
cnt++; //按鍵次數+1
if (cnt >= 10)
{ //只用1個數碼管顯示，所以加到10就清零重新開始
cnt = 0;
}
P0 = LedChar[cnt]; //計數值顯示到數碼管上
}
backup = keybuf; //更新備份為當前值，以備進行下次比較
}
}
}
}
/* 軟件延時函數，延時約10ms */
void delay()
{
unsigned int i = 1000;
while (i--);
}
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