24c02(1).asm

这是一个24C02的汇编程序！24C02是外部存储器！在设计中用到这个

#define uchar unsigned char 
#define uint  unsigned int
#define ulong unsigned long
#include <reg52.h>     


char code dx516[3] _at_ 0x003b;

#define	WriteDeviceAddress 0xa0	  
#define	ReadDviceAddress 0xa1
sbit	SCL=P3^7;
sbit	SDA=P3^6;

sbit 	P00=P0^0;


void DelayMs(uint number) 
{
	uchar temp;
	for(;number!=0;number--) 
	{
		for(temp=112;temp!=0;temp--) ;
	}
}


void Start() 
{
	SDA=1;
	SCL=1;
	SDA=0;
	SCL=0;
}


void Stop() 
{
	SCL=0;
	SDA=0;
	SCL=1;
	SDA=1;
}


bit TestAck() 
{
	bit ErrorBit;
	SDA=1;
	SCL=1;
	ErrorBit=SDA;
	SCL=0;
	return(ErrorBit);
}


Write8Bit(uchar input) 
{
	uchar temp;
	for(temp=8;temp!=0;temp--) 
	{
		SDA=(bit)(input&0x80);
		SCL=1;
		SCL=0;
		input=input<<1;
	}
}


void Write24c02(uchar ch,uchar address) 
{
	Start();
	Write8Bit(WriteDeviceAddress);
	TestAck();
	Write8Bit(address);
	TestAck();

	Write8Bit(ch);
	TestAck();
	
	Stop();
	DelayMs(10);
}


void main(void)	
{
	Write24c02(0x88,0x02);
	
	P00=0; 
	while(1); 


}