第1个回答 2017-04-19
#include<reg51.h>
sbit key1=P2^5;
sbit key2=P2^6;
sbit key3=P2^7;
main()
{
bit flag=0;
unsigned char a;
while(1)
{
if(key1==0)
{
while(key1==0);
if(flag==0)a++;
else a--;
P0=a;
}
if(key2==0)
{
while(key2==0);
if(flag==0)a--;
else a++;
P0=a;
}
if(key3==0){while(key1==0);flag=~flag;}
}
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