按键盘数码管流动显示实验

#include  <reg52.h>
#define   LEDLen   6

xdata unsigned char OUTBIT _at_ 0x8002;   // 位控制口
xdata unsigned char OUTSEG _at_ 0x8004;   // 段控制口
xdata unsigned char IN     _at_ 0x8001;   // 键盘读入口

unsigned char LEDBuf[LEDLen];    // 显示缓冲
code unsigned char LEDMAP[] = {  // 八段管显示码 (点不显示，0-F）
0x3f, 0x06, 0x5b, 0x4f, 0x66, 0x6d, 0x7d, 0x07,
0x7f, 0x6f, 0x77, 0x7c, 0x39, 0x5e, 0x79, 0x71
};

code unsigned char KeyTable[] = {   // 键码定义
0x16, 0x15, 0x14, 0xff,
0x13, 0x12, 0x11, 0x10,
0x0d, 0x0c, 0x0b, 0x0a,
0x0e, 0x03, 0x06, 0x09,
0x0f, 0x02, 0x05, 0x08,
0x00, 0x01, 0x04, 0x07
};

void Delay(unsigned char CNT)
{
unsigned char i;
while (CNT-- !=0)
for (i=100; i !=0; i--);
}

void DisplayLED()
{
unsigned char i;
unsigned char Pos;
unsigned char LED;

Pos = 0x20;       // 从左边开始显示
for (i = 0; i < LEDLen; i++) {
OUTBIT = 0;     // 关所有八段管
LED = LEDBuf[i];
OUTSEG = LED;
OUTBIT = Pos;   // 显示一位八段管
Delay(2);
Pos >>= 1;      // 显示下一位
}
}

unsigned char TestKey()
{
OUTBIT = 0;            // 输出线置为0
return (~IN & 0x0f);   // 读入键状态(高四位不用)
}

unsigned char GetKey()
{
unsigned char Pos;
unsigned char i;
unsigned char k;

i = 6;
Pos = 0x20;     // 找出键所在列
do {
OUTBIT = ~ Pos;
Pos >>= 1;
k = ~IN & 0x0f;
} while ((--i != 0) && (k == 0));

// 键值 = 列 x 4 + 行
if (k != 0)
{
i *= 4;
if (k & 2)
i += 1;
else if (k & 4)
i += 2;
else if (k & 8)
i += 3;

OUTBIT = 0;
do
Delay(10); while (TestKey());  // 等键释放

return(KeyTable[i]);  // 取出键码
} else return(0xff);
}

void main()
{    unsigned int i=0;
LEDBuf[0] = 0x00;  //如果设置为3F那么最初第一个数码管显示为0
LEDBuf[1] = 0x00;
LEDBuf[2] = 0x00;
LEDBuf[3] = 0x00;
LEDBuf[4] = 0x00;
LEDBuf[5] = 0x00;

while (1) {
DisplayLED();
if (TestKey())
{

LEDBuf[i++%6] = LEDMAP[GetKey() & 0x0f];
//LEDBuf[5]=LEDMP[GetKey()&0x0f];
}
}
}