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设计仿真实例的运行文件及C程序

#include<reg51.h>
unsigned char xdata *con=0xff7f; /*定义8255控制寄存器地址指针*/
unsigned char xdata *pc=0xff7e;	 /*定义8255PC口地址指针8*/
unsigned char i=5;		/*设置定时器定时次数*/
sbit A5=0xE5;		  /*定义ACC的A^5位方便取反操作*/
void main()
{
	ACC=0xff;
	*con=0x80;
	TMOD=0x02;
	TL0=0x38;
	TH0=0x38;
	ET0=1;
	EA=1;
	TR0=1;
	while(1)
	{;}
}
void timer0() interrupt 1 using 0
{
	if(i>0)
	{i--;}
	else 
	{
	ACC=*pc;
	A5=~A5;		   /*取反并送回，实现发生方波*/
	*pc=ACC;
	i=5;	
	}	
}