#include <stdio.h>

void encrypt(void)
{
	int j;
	printf("Encryption of data ...");
	for(j=0;j<=0x3fff;++j);
}

void decrypt(void)
{
	int j;
	printf("Decryption of data ...");
	for(j=0;j<=0x3fff;++j);
}
void main(void)
{
	unsigned char i,*porta,*ddra;
	porta=(unsigned char *)0x00;
	ddra=(unsigned char *)0x01;
	if(*porta==0)
	{
		encrypt();
		*porta=2;
	}
	else
	{
		decrypt();
		*porta=4;
	}
}