c51单片机外部中断
用C语言写一个外部中断程序，用按键改变频率。要求用外部中断0，每按一次就进入中断改变一次频率，当改变3次之后再按下就跳出中断
下次再按这个开关的时候还能进入，最好要有注释
第1个回答 2017-12-11
sbit p32=P3^2;
void ext0() interrupt 0
{
unsigned num=0;
while(num<4)
{
while(p32==0);
num++;
freq+=100;
}
}追问
#define uchar unsigned char
#define uint unsigned int
uint fre,cnt;
sbit pluse=P1^0;
sbit key=P3^2;
void t0isr() interrupt 1
{
cnt++;
if(cnt>=fre)
{
pluse=~pluse;
cnt=0;
}
}
void ext0() interrupt 0
{
unsigned num=0;
while(num<4)
{
while(key==0);
num++;
freq+=100;
}
}
main()
{
TMOD=0x02;
TH0=250;
TL0=250;
TR0=1;
ET0=1;
EA=1;
fre=100;
while(1);
}本回答被提问者采纳
void ext0() interrupt 0
{
unsigned num=0;
while(num<4)
{
while(p32==0);
num++;
freq+=100;
}
}追问
您好，您能够写的具体点么。我有点菜，不是特别懂
追答#include<reg51.h>#define uchar unsigned char
#define uint unsigned int
uint fre,cnt;
sbit pluse=P1^0;
sbit key=P3^2;
void t0isr() interrupt 1
{
cnt++;
if(cnt>=fre)
{
pluse=~pluse;
cnt=0;
}
}
void ext0() interrupt 0
{
unsigned num=0;
while(num<4)
{
while(key==0);
num++;
freq+=100;
}
}
main()
{
TMOD=0x02;
TH0=250;
TL0=250;
TR0=1;
ET0=1;
EA=1;
fre=100;
while(1);
}本回答被提问者采纳
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