關于單片機LED數字倒計時的程序但是看不太懂

ID:194564 · 發表于 2017-5-2 15:02

我網上找了一個關于單片機LED數字倒計時的程序但是看不太懂
有沒有大神幫我注釋一下意思再弄個protues 仿真電路圖

# include <reg51.h>
sbit kh=P1^1;
sbit km=P1^1;
sbit ks=P1^2;
sbit st=P1^3;
sbit b=P3^7;
unsigned char
table[]={0xc0,0xf9,0xa4,0xb0,0x99,0x92,0x82,0xf8,0x80,0x90,0x88, 0x83,0xc6,0xa1,0x86,0x8e};
unsigned char i=0,hour=0,minute=0,second=0;

void delayms(unsigned int x)

{ unsigned char a=160;

while(x--) { while(a--); a=160; } }

main() { TH0=(65536-50000)/256;

TL0=(65536-50000)%256;

TMOD=1;

TR0=0;

ET0=1;

EA=1;

while(1) {

P0=table[hour/10];

P2=0x20;

delayms(1);

P2=0xff;

P0=table[hour%10];

P2=0x10;

delayms(1);

P2=0xff;

P0=table[minute/10];

P2=0x08;

delayms(1);

P2=0xff;

P0=table[minute%10];

P2=0x04;

delayms(1);

P2=0xff;

P0=table[second/10];

P2=0x02;

delayms(1);

P2=0xff;

P0=table[second%10];

P2=0x01;

delayms(1);

P2=0xff;

if(!kh)

{ delayms(200);

hour++;

if(hour>23)

hour=23; }

else if(!km)

{ delayms(200);

minute++;

if(minute>59)

minute=59; }

else if(!ks)

{ delayms(200);

second++;

if(second>59)

second=59; }

if(!st)

{ delayms(200);

TR0=1; }

if(TR0==1&&hour==0&&minute==0&&second<3) b=!b; delayms(1); } }

void t0() interrupt 1 { TH0=(65536-50000)/256; TL0=(65536-50000)%256;

i++;

if(i>=20)

{ i=0; second--;

if(second>59)

{ second=59;

minute--;

if(minute>59)

{ minute=59;

hour--;

if(hour>23)

{hour=0; minute=0; second=0; TR0=0; } } } } }