eeprom.c

用MCS51 单片机的TCIP协议的测试,很基本的程序,对新手可能有帮助!

/*
********************************************************************************
* Wiznet.
* 5F Simmtech Bldg., 228-3, Nonhyun-dong, Kangnam-gu,
* Seoul, Korea
*
* (c) Copyright 2002, Wiznet, Seoul, Korea
*
* Filename      : eeprom.c
* Programmer(s) : 
* Version       : 1.0 
* Created       : 2002/06/1
* Modified      :
* Description   : 
********************************************************************************
*/
#include "config.h"
#include "eeprom.h"

void eep_delay(unsigned int num)
{
	unsigned int i,j;
	
	for(i=0;i<num;i++)
	  for(j=0;j < 400; j++)
	  ;
}

void eep_sendstart(void)
{
	P1 |= SDA_H;	//SDA HIGH
	P1 |= SCL_H;	//SCL HIGH
	P1 &= SDA_L;	//SDA LOW
	P1 &= SCL_L;	//SCL LOW
}

void eep_sendend(void)
{
	P1 &= SCL_L;	// SCL LOW
	P1 &= SDA_L;	// SDA LOW
	P1 |= SCL_H;	// SCL HIGH;
	P1 |= SDA_H;   // SDA HIGH;
}

char eep_checkack(void)
{
	char ack;
	
	P1 &= SCL_L;
	P1 |= SCL_H;
	ack = P1 & 0x08;	
	P1 &= SCL_L;
	return ack;
}

void eep_sendnoack(void)
{
	P1 &= SCL_L;
	P1 |= SDA_H; // High
	// SCL Clock
	P1 |= SCL_H;
	P1 &= SCL_L;
}

void eep_writedata(unsigned char b)
{
	char i;
	
	EA = 0;
	for(i = 0 ; i < 8  ; i++) 
	{
		P1 &= SCL_L;   //SCL LOW
		if( ((b << i) & 0x80) )  
			P1 |= SDA_H;
		else					 
			P1 &= SDA_L;
		eep_delay(1);
		P1 |= SCL_H;	//SCL HIGH
	}
	P1 &= SCL_L;  // SCL LOW
	EA = 1;
	
}

char eep_readdata(void)
{
	char ret;
	char i;
	
	ret = 0;
	EA = 0;
	P1 &= SCL_L;	// SCL LOW
	for(i = 7; i >=0  ; i--)
	{
		P1 |= SCL_H;;	// SCL HIGH
		if (P1 & SDA_H) ret |= (1<<i); ;  
		P1 &= SCL_L;	// SCL LOW
	}
	EA = 1;
	return ret;
}


/*
********************************************************************************
* Description : Serial EEPROM Write routine
* Arguments   : ee_addr - write position, ee_data - data
* Returns     : None
* Note        : 
********************************************************************************
*/
void EEP_Write(unsigned char ee_addr,unsigned char ee_data)
{
    eep_sendstart();
	eep_writedata(0xa0); //  H/W address
	eep_checkack();
	eep_writedata(ee_addr); // addr
	eep_checkack();
	eep_writedata(ee_data); //data
	eep_checkack();
	eep_sendend();
	
	eep_delay(10);
}

/*
********************************************************************************
* Description : Serial EEPROM Read routine
* Arguments   : ee_addr - read position
* Returns     : EEPROM data
* Note        : 
********************************************************************************
*/
unsigned char EEP_Read(unsigned char ee_addr)
{
	unsigned char ee_data;

    eep_sendstart();
	eep_writedata(0xa0);
	eep_checkack();
	eep_writedata(ee_addr);
	eep_checkack();
	eep_sendstart();
	eep_writedata(0xa1);
	eep_checkack();
	ee_data = eep_readdata();
	eep_sendnoack();
	eep_sendend();

	return ee_data;
}