c51单片机 独立按键

用独立按键实现按一个按键时，数字从F到0递减的变化程序，即每按一次按键，数码管显示字符减一，减到0后重新显示。

#include

sbit ADDR0= P2^2;

sbit ADDR1=P2^3;

sbit ADDR2=P2^4;

sbit key1=P3^0;

unsigned char code ledchar[] = {0x00,0xc0,0xf9,0xa4,0xb0,0x99,0x92,0x82,

0xf8,0x80,0x90,0x88,0x83,0xc6,0xa1,0x86,0x8e};

bit keysta = 1;

void main()

{

bit backup = 1;

unsigned char cnt = 16;

EA  = 1;

ADDR2 =0;

ADDR1= 0;

ADDR0 = 0;

TMOD = 0X01;

TH0 = 0XF8;

TL0 = 0XCD;

ET0 = 1;

TR0 = 1;

P0 = ~ledchar[cnt];

while(1)

{

if(keysta != backup)

{

if(backup == 0)

{

cnt--;

if(cnt < 1)

{

cnt = 16;

}

P0 = ~ledchar[cnt];

}

backup  = keysta;

}

}

}

void InterruptTimer0() interrupt 1

{

static unsigned char keybuf = 0xff;

TH0 = 0XF8;

TL0 = 0XCD;

keybuf = (keybuf <<1)|key1;

if(keybuf == 0x00)

{

keysta = 0;

}

else if(keybuf == 0xff)

{

keysta = 1;

}

else

{}

}

c51独立按键