main.c

《Proteus在MCS-51&ARM7系统中的应用百例》逆向之 Chapter 4 《Proteus在MCS-51&ARM7系统中的应用百例》MCS-51例子的C语言版本。

#include <reg51.h>
typedef unsigned char BYTE;

BYTE LINE _at_ 0x30;
BYTE ROW  _at_ 0x31;
BYTE VAL  _at_ 0x32;

sbit P30=P3^0;
sbit P31=P3^1;
sbit P32=P3^2;
sbit P33=P3^3;
sbit P34=P3^4;
sbit P35=P3^5;
sbit P36=P3^6;
sbit P37=P3^7;

BYTE code TABLE[]={0x3F,0x06,0x5B,0x4F,0x66,0x6D,0x7D,0x07,
				   0x7F,0x6F,0x77,0x7C,0x39,0x5E,0x79,0x71};


void DELAY()
{
	BYTE i=20;
	
	do
	{
		BYTE j=250;
		do
		{}while(--j);
	}while(--i);
}



main()
{
	P2=0x00;

	while(1)
	{
		P3=0xF0;
	
		while(1)
		{
			if(P30)
			{
				DELAY();
	
				if(P30)
				{
					LINE=0x00;	break;
				}		
			}
	
			if(P31)
			{
				DELAY();
	
				if(P31)
				{
					LINE=0x01;	break;
				}		
			}
	
			if(P32)
			{
				DELAY();
	
				if(P32)
				{
					LINE=0x02;	break;
				}		
			}
	
			if(P33)
			{
				DELAY();
	
				if(P33)
				{
					LINE=0x03;	break;
				}		
			}
		}//end while
	
		P3=0x0F;
	
		while(1)
		{
			if(P34)
			{
				ROW=0x00;	break;
			}
			if(P35)
			{
				ROW=0x01;	break;
			}
			if(P36)
			{
				ROW=0x02;	break;
			}
			if(P37)
			{
				ROW=0x03;	break;
			}
		}//end while
	
		VAL=ROW+LINE*0x04;
		P2=TABLE[VAL];
	}
	
}