Question

如何用外部中断1实现第一个数码管0-9循环，按下按键后计数暂停，再按下后继续计数？

89C51单片机，用C语言编程，谢谢！

Answer 1

#include<reg51.h>
#define uchar unsigned char
uchar table[]={0x3f,0x06,0x5b,0x4f,0x66,0x6d,0x7d,0x07,0x7f};
sbit key=P1^0;
void delay(uchar a)
{
uchar i;
while(1--)for(i=0;i<120;i++);
}
main()
{
uchar num=0;
bit flag=0;
whilie(1)
    {
    P0=table[num];
    P2=0x0fe;
    delay(200);
    if(flag==0)num++;
    if(key==0)
        {
        while(key==0);
        flag=~flag;
        }
    }
}