C51单片机：用数码管显示0到999的值。求c语言程序和原理图

#include

#define uchar unsigned char

uchar temp;

int key1,key,disbuf;// 此表为 LED 的字模 0 1 2 3 4 5 6 7 8 9 a b c d e f

unsigned char code LED7Code[] = {0x3F,0x06,0x5B,0x4F,0x66,0x6D,0x7D,0x07,0x7F,0x6F,0x77,0x7C,0x39,0x5E,0x79,0x71};

unsigned char ledx[8];

bit s0,s1;

void delay(uchar z)

{

uchar i,j;

for(i=0;i<120;i )

for(j=0;j

}

void scan() ///如果按，扫描键盘编码值

{

P1=0xF0;

delay(1);

temp=P1;

switch(temp)

{

case 0xe0: key1=0;

break;

case 0xd0: key1=1;

break;

case 0xb0: key1=2;

break;

case 0x70: key1=3;

break;

}

P1=0x0f;

delay(1);

temp=P1;

switch(temp)

{

case 0x0E: key=key1 0;

break;

case 0x0D: key=key1 4;

break;

case 0x0B: key=key1 8;

break;

case 0x07: key=key1 12;

break;

default : key=-1;

}

if((key1 1)&&(key 1)) disbuf=key;

}

void ejjc() //判断是否按键

{

P1=0xF0;

if(P1!=0xF0) { scan();s0=1;}

else { s0=0; s1=1;}

}

void main()

{

uchar i;

while(1)

{

ejjc();

if(s0==1 && s1==1)

{

s0=0;s1=0;

for(i=0;i<8;i )

{ ledx[i]=ledx[i 1]; ledx[8]=disbuf; }

}

P0=0xff;

P2=LED7Code[ledx[0]];

P0=0xfe;

delay(5);

P0=0xff;

P2=LED7Code[ledx[1]];

P0=0xfd;

delay(5);

P0=0xff;

P2=LED7Code[ledx[2]];

P0=0xfb;

delay(5);

P0=0xff;

P2=LED7Code[ledx[3]];

P0=0xf7;

delay(5);

P0=0xff;

P2=LED7Code[ledx[4]];

P0=0xef;

delay(5);

P0=0xff;

P2=LED7Code[ledx[5]];

P0=0xdf;

delay(5);

P0=0xff;

P2=LED7Code[ledx[6]];

P0=0xbf;

delay(5);

P0=0xff;

P2=LED7Code[ledx[7]];

P0=0x7f;

delay(5);

}

}