#include "REG52.h"http://
#include "intrins.h"http://

sbit Row0 = P1^0;
sbit Row1 = P1^1;
sbit Row2 = P1^2;
sbit Row3 = P1^3;
sbit Col0 = P1^4;
sbit Col1 = P1^5;
sbit Col2 = P1^6;
sbit Col3 = P1^7;

unsigned char KeyScan(void);

void main(void)
{
KeyScan();
while(1);
}

unsigned char KeyScan(void)
{
unsigned char key, temp;
unsigned char code keytab[] = {//鍵碼表
//鍵值,//點,鍵名 鍵號
0x81,//07,key1 00
0x41,//06,key2 01
0x21,//05,key3 02
0x11,//04,key4 03

0x82,//17,key5 04
0x42,//16,key6 05
0x22,//15,key7 06
0x12,//14,key8 07

0x84,//27,key9 08
0x44,//26,key10 09
0x24,//25,key11 0A
0x14,//24,key12 0B

0x88,//37,key13 0C
0x48,//36,key14 0D
0x28,//35,key15 0E
0x18,//34,key16 0F

0x03,//01,key17 10
0x06,//12,key18 11
0x0c,//23,key19 12
0x05,//02,key20 13
0x09,//03,key21 14
0x0d,//13,key22 15

0xc0,//67,key23 16
0x60,//56,key24 17
0x30,//45,key25 18
0xa0,//57,key26 19
0x50,//46,key27 1A
0x90,//47,key28 1B

/*
0x01,//G0,key29 1C
0x02,//G1,key30 1D
0x04,//G2,key31 1E
0x08,//G3,key32 1F
0x10,//G4,key33 20
0x20,//G5,key34 21
0x40,//G6,key35 22
0x80,//G7,key36 23
*/
0//退出
};
P1 = 0xff;//釋放鍵盤
_nop_();//延時
key = P1;//測試獨占鍵(與GND連接)
key = ~key;//取反，變?yōu)檎�邏�?
if (key) {//有獨占鍵壓下，鍵碼28~35，鍵key29..key36
temp = 35;//最后一個獨占鍵key36
do {
if (key >= 0x80) break;//有獨占鍵壓下,退出測試
key <<= 1;//測試下一獨占鍵
temp --;//鍵號-1
}
while(key);//未測完繼續(xù)
if (key != 0x80) key = 0xff;//多個獨占鍵壓下,出錯鍵碼0xff
else key = temp;//得到鍵碼28~35,鍵號key29~key36.
}
else {//測試組合鍵，鍵碼0~27
temp = 0x01;//實為從P1_1測起，到P1_7測完
do {//只需掃描7次！��！
temp <<= 1;//繼續(xù)掃描下一位
P1 = ~temp;//發(fā)送某位低電平
_nop_();//延時
key = P1;//接收鍵盤數(shù)據(jù)
key = ~key;//取反，變?yōu)檎�邏�?
}
while((temp < 0x80) && (key == temp));//測到P1_6或有鍵壓下結(jié)束
if (key == temp) key = 0xff;//無鍵壓下，鍵碼0xff
else {//有組合鍵壓下
temp = 0;//初始鍵號
while(keytab[temp] && (key != keytab[temp])) temp ++;//查鍵值表
if (temp >= 28) temp = 0xff;//查無此組合鍵，出錯鍵碼0xff
else key = temp;//得到組合鍵碼0~27，鍵key1~key28.
}
}
return key;//返回鍵碼0~35或出錯碼0xff
}