51 EEPROM操作模板

各个型号容量及扇区请查datasheet

#include <reg52.h>
#include "intrins.h"

typedef unsigned char byte;
typedef unsigned int word;

/* Declare SFR associated with the IAP */
sfr IAP_DATA  = 0xC2;  //Flash data register
sfr IAP_ADDRH = 0xC3;  //Flash address HIGH
sfr IAP_ADDRL = 0xC4;  //Flash address LOW
sfr IAP_CMD   = 0xC5;  //Flash command register
sfr IAP_TRIG  = 0xC6;  //Flash command trigger
sfr IAP_CONTR = 0xC7;  //Flash control register

/* Define ISP/IAP/EEPROM command */
#define CMD_IDLE 0	   //Stand-By
#define CMD_READ 1	   //Byte-Read
#define CMD_PROGRAM 2  //Byte-Program
#define CMD_ERASE 3	   //Sector-Erase

/* Define ISP/IAP/EEPROM operation const for IAP_CONTR */
#define ENABLE_IAP 0x80	 //if SYSCLK < 30MHz
#define ENABLE_IAP 0x81	 //if SYSCLK < 24MHz
#define ENABLE_IAP 0x82	 //if SYSCLK < 20MHz
#define ENABLE_IAP 0x83	 //if SYSCLK < 12MHz
#define ENABLE_IAP 0x84	 //if SYSCLK < 6MHz
#define ENABLE_IAP 0x85	 //if SYSCLK < 3MHz
#define ENABLE_IAP 0x86	 //if SYSCLK < 2MHz
#define ENABLE_IAP 0x87	 //if SYSCLK < 1MHz

//Start address for STC12C5201AD series EEPROM
#define IAP_ADDRESS 0x0000

void Delay(byte n)
{
	word x;
	while(n--)
	{
		x = 0;
		while(++x);
	}
}

/* Disable ISP/IAP/EEPROM function Make MCU in a safe state */

void IapIdle()
{
	 IAP_CONTR = 0;		   //close IAP function
	 IAP_CMD = 0;		   //clear command to standby
	 IAP_TRIG = 0;		   //clear tirgger register
	 IAP_ADDRH = 0x80;	   //data ptr point to non EEPROM area
	 IAP_ADDRL = 0;		   //clear IAP address to prevent mususe
}

/* read one byte from isp/iap/eeprom area input:addr(isp iap eeprom address) output:flash data */
byte IapReadByte(word addr)
{
	byte dat;

	IAP_CONTR = ENABLE_IAP; //Open IAP function and set wait time
	IAP_CMD = CMD_READ;	    //Set ISAP READ command
	IAP_ADDRL = addr;       //Set ISP address low
	IAP_ADDRH = addr >> 8;  //Set IAP address high
	IAP_TRIG = 0x5a;        //Send trigger command1(0x5a)
	IAP_TRIG = 0xa5;        //Send trigger command2(0xa5)
	_nop_();				//MCU will hold here until IAP operation complete

	dat = IAP_DATA; 		//Read IAP EEPROM data
	IapIdle();				//Close ISP function

	return dat;				//Return Flash data
}

/* Program one byte to ISP area   Input:addr (address)  dat(data)  Output:- */
void IapProgramByte(word addr, byte dat)
{
	IAP_CONTR = ENABLE_IAP;		//Open IAP function, and set wait time
	IAP_CMD   = CMD_PROGRAM;    //Set EEPROM PROGRAM command
	IAP_ADDRL = addr;
	IAP_ADDRH = addr >> 8;
	IAP_DATA = dat;
	IAP_TRIG = 0x5a;
	IAP_TRIG = 0xa5;
	_nop_();

	IapIdle();
}

/* Erase one sector area Input:addr */
void IapEraseSector(word addr)
{
	IAP_CONTR = ENABLE_IAP;
	IAP_CMD = CMD_ERASE;
	IAP_ADDRL = addr;
	IAP_ADDRH = addr >> 8;
	IAP_TRIG = 0x5a;
	IAP_TRIG = 0xa5;
	_nop_();

	IapIdle();
}

int main()
{
	word i;

	P1 = 0xfe;
	Delay(10);
	IapEraseSector(IAP_ADDRESS);

	for(i = 0; i < 512; ++i)
	{
		if(IapReadByte(IAP_ADDRESS + i) != 0xff)
		{}
	}

	P1 = 0xfc;
	Delay(10);
	for(i = 0; i < 512; ++i)
	{
		IapProgramByte(IAP_ADDRESS + i, (byte)i);
	}

	P1 = 0xf8;
	Delay(10);
	for(i = 0; i < 512; ++i)
	{
		if(IapReadByte(IAP_ADDRESS + i) != (byte)i)
		{}
	}

	P1 = 0xf0;
	while(1);

	return 0;
}