網(wǎng)上流傳比較多的C51版本是龐波的《25045操作標(biāo)準(zhǔn)子程序集41.c》，但是經(jīng)我實(shí)際使用過后發(fā)現(xiàn)有一些錯(cuò)誤，如&和&&的區(qū)別及一些邏輯的問題。還有總是有人問電路的接法，由于X25045的datasheet寫的不清楚，的確很容易弄錯(cuò)，這次就把接法的說明也貼上來(lái)了。希望能夠?qū)Υ蠹矣袔椭?br/>分為兩個(gè)文件：X25045.h和X25045.C內(nèi)容如下
1、X25045.h

#ifndef __X25045_H__
#define __X25045_H__
/*
;軟 件 標(biāo) 題：25045操作標(biāo)準(zhǔn)子程序集
;軟 件 說 明：X25045已經(jīng)停產(chǎn)，替代產(chǎn)品為X5045
;_________________________________________

;原作者:龐波
;程序修改人：貓賊
;版本號(hào)：
;_________________________________________
;貓賊：感謝原作者提供參考程序，雖然其中有一些錯(cuò)誤，但是其公開源碼的方式值得敬佩。
;我沒有測(cè)試連續(xù)讀和連續(xù)寫程序，不知道會(huì)不會(huì)有問題，其他的函數(shù)都已經(jīng)正確了。
*/
/*
參考電路說明：X25045/X5045
PIN1-CS :直接接到MCU的IO口
2-SO :直接接到MCU的IO口
3-WP :電阻上拉5V, 個(gè)人感覺接到MCU的IO口沒什么意義
4-VSS:GND
5-SI :直接接到MCU的IO口
6-SCK:直接接到MCU的IO口
7-RST:電阻上拉5V，該引腳直接與MCU的RST腳相連,注意該引腳不能接下拉電阻
8-VCC:+5V
應(yīng)用范例:
環(huán)境：AT89C2051,+5V供電,6MHz晶振頻率
編譯器：偉福，Keil C
1.設(shè)置狀態(tài)寄存器(設(shè)置/開啟Watchdog)。狀態(tài)寄存器的值請(qǐng)?jiān)O(shè)置STATUS_REG
void main(void){
wrsr_cmd();//復(fù)位時(shí)間位和數(shù)據(jù)保護(hù)位寫入狀態(tài)寄存器
//該語(yǔ)句最好放在起始位置，執(zhí)行完畢后Watchdog就設(shè)置為需要的時(shí)間參數(shù)。
//Watchdog其實(shí)在上電的時(shí)候就已經(jīng)開始計(jì)時(shí)了，默認(rèn)的時(shí)間為1.4秒。
//狀態(tài)寄存器值默認(rèn)為00
//注意不要忘記喂狗rst_wdog();
........
}
2.寫/讀一個(gè)字節(jié)到EEPROM。
void main(void){
..........
byte_write(0x55,0x01);//寫一個(gè)字節(jié)數(shù)據(jù)0x55到的EEPROM，地址0x01
..........
Array_Vector = byte_read(0x01);//讀取0x01地址的內(nèi)容，如果之前沒有做過改變，則應(yīng)該為0X55
..........
}

*/

sbit SO =P1^3;/*25045輸出*/
sbit SI =P1^5;/*25045輸入*/
sbit SCK=P1^6;/*25045時(shí)鐘*/
sbit CS =P1^4;/*25045片選*/

#define STATUS_REG 0X00
/* Status register,設(shè)置DOG時(shí)間設(shè)置為1.4秒,無(wú)寫保護(hù)
這是狀態(tài)寄存器的值,他的意義在于第5,第4位為WDI1,WDI0代表DOG的時(shí)間,00為1.4秒,01為600毫秒,10為200毫秒,00為dISAbLED
第3位和第2位為BL1,BL0,是寫保護(hù)設(shè)置位,00為無(wú)保護(hù),01為保護(hù)180-1FF,10為保護(hù)100-1FF,11為保護(hù)000-1FF.第1位為WEL,
當(dāng)他為1時(shí)代表已經(jīng)"寫使能"設(shè)置了,現(xiàn)在可以寫了,只讀位.第0位為WIP,當(dāng)他為1時(shí)代表正在進(jìn)行寫操作,是只讀*/
#define MAX_POLL0x99
/* Maximum number of polls
最大寫過程時(shí)間,確定25045的最大的寫入過程的時(shí)間*/

void wren_cmd(void);/*寫使能子程序*/
void wrdi_cmd(void);/*寫使能復(fù)位*/
void wrsr_cmd(void);/*復(fù)位時(shí)間位和數(shù)據(jù)保護(hù)位寫入狀態(tài)寄存器*/
unsigned char rdsr_cmd(void);/*讀狀態(tài)寄存器*/
void byte_write(unsigned char aa,unsigned int dd);/*字節(jié)寫入,aa為寫入的數(shù)據(jù),dd為寫入的地址*/
unsigned char byte_read(unsigned int dd);/*字節(jié)讀出,dd為讀出的地址,返回讀出的數(shù)據(jù)*/
void page_write(unsigned char aa1,unsigned char aa2,unsigned char aa3,unsigned char aa4,unsigned int dd);/*頁(yè)寫入*/
void sequ_read(void);/*連續(xù)讀出*/
void rst_wdog(void);/*DOG復(fù)位*/

#endif/* __X25045_H__ */


2、X25045.C

#include
#include
#include "X25045.H"
#define uchar unsigned char
#define uint unsigned int

uchar code WREN_INST=0X06;
/* Write enable latch instruction (WREN)*/
uchar code WRDI_INST=0X04;
/* Write disable latch instruction (WRDI)*/
uchar code WRSR_INST=0X01;
/* Write status register instruction (WRSR)*/
uchar code RDSR_INST=0X05;
/* Read status register instruction (RDSR)*/
uchar code WRITE_INST=0X02;
/* Write memory instruction (WRITE)*/
/*寫入25045的先導(dǎo)字,應(yīng)當(dāng)為0000A010,其中的A為寫入25045的高位地址
將此WRITE_INST和寫入高位地址相或后即為正確的寫先導(dǎo)字*/
uchar code READ_INST=0X03;
/* Read memory instruction (READ)*/
/*讀出25045的先導(dǎo)字,應(yīng)當(dāng)為0000A011,其中的A為讀出25045的高位地址
將此READ_INST和讀出高位地址相或后即為正確的讀先導(dǎo)字*/
uint code BYTE_ADDR=0X55;
/* Memory address for byte mode operations*/
uchar code BYTE_DATA=0X11;
/*Data byte for byte write operation*/
uintcode PAGE_ADDR=0X1F;
/* Memory address for page mode operations*/
/*頁(yè)面寫入的其始地址*/
uchar code PAGE_DATA1=0X22;
/* 1st data byte for page write operation*/
uchar code PAGE_DATA2=0X33;
/* 2nd data byte for page write operation*/
uchar code PAGE_DATA3=0X44;
/* 3rd data byte for page write operation*/

uchar code INIT_STATE=0x09;
/* Initialization value for control ports*/
uint code SLIC=0x30;
/* AddressLOCation of SLIC*/

void outbyt(uchar aa);/*輸出一個(gè)字節(jié)到25045中，不包括先導(dǎo)字等*/
uchar inputbyt();/*由25045輸入一個(gè)字節(jié)，不包括先導(dǎo)字等額外的東西*/
void wip_poll(void);/*檢查寫入過程是否結(jié)束*/


void delay(char n){
char a;
for(a=0;a}
/*25045操作子程序集*/
/*;**********************************************************
*
;* Name: WREN_CMD
;* Description: Set write enable latch
;* Function: This routine sends the command to enable writes to the EEPROM memory array or
;* status register
;* Calls: outbyt
;* Input: None
;* Outputs: None
;* Register Usage: A
;**************************************************************
*/
/*寫使能子程序*/
void wren_cmd(void)
{
uchar aa;
SCK=0;/* Bring SCK low */
CS=0;/* Bring /CS low */
aa=WREN_INST;
outbyt(aa);/* Send WREN instruction */
delay(1);
SCK=0;/* Bring SCK low */
CS=1;/* Bring /CS high */
}

/*;********************************************************************
*
;* Name: WRDI_CMD
;* Description: Reset write enable latch
;* Function: This routine sends the command to disable writes to the EEPROM memory array or
;* status register
;* Calls: outbyt
;* Input: None
;* Outputs: None
;* Register Usage: A
;********************************************************************
*/
/*寫使能復(fù)位子程序*/
void wrdi_cmd(void)
{
uchar aa;
SCK=0;/* Bring SCK low */
CS=0;/* Bring /CS low */
aa=WRDI_INST;
outbyt(aa);/* Send WRDI instruction */
delay(1);
SCK=0;/* Bring SCK low */
CS=1;/* Bring /CS high */
}


/*;***********************************************************************
*
;* Name: WRSR_CMD
;* Description: Write Status Register
;* Function: This routine sends the command to write the WD0, WD1, BP0 and BP0 EEPROM
;* bits in the status register
;* Calls: outbyt, wip_poll
;* Input: None
;* Outputs: None
;* Register Usage: A
;**********************************************************************
*/
/*寫狀態(tài)寄存器子程序*/
void wrsr_cmd(void)
{
uchar aa;

wren_cmd();//寫使能子程序

SCK=0;/* Bring SCK low */
CS=0;/* Bring /CS low */
aa=WRSR_INST;
outbyt(aa) ;/* Send WRSR instruction */
aa=STATUS_REG;
outbyt(aa);/* Send status register */
delay(1);
SCK=0;/* Bring SCK low */
CS=1;/* Bring /CS high */
wip_poll();/* Poll for completion of write cycle */

wrdi_cmd();//寫使能復(fù)位,其實(shí)這句可以省略，每寫一次就自動(dòng)復(fù)位
}





/*;*************************************************************************
*
;* Name: RDSR_CMD
;* Description: Read Status Register
;* Function: This routine sends the command to read the status register
;* Calls: outbyt, inputbyt
;* Input: None
;* Outputs: A = status registerXicor Application Note AN21
;* Register Usage: A
;********************************************************************
*/
/*讀狀態(tài)寄存器,讀出的數(shù)據(jù)放入到aa中*/
uchar rdsr_cmd (void)
{
uchar aa;
SCK=0;
CS=0;
aa=RDSR_INST;
outbyt(aa);
aa=inputbyt();
SCK=0;
CS=1;
return aa;
}







/*;**********************************************************************
*
;* Name: BYTE_WRITE
;* Description: Single Byte Write
;* Function: This routine sends the command to write a single byte to the EEPROM memory
array
;* Calls: outbyt, wip_poll
;* Input: None
;* Outputs: None
;* Register Usage: A, B
;***************************************************************
*/
/*字節(jié)寫入,aa為寫入的數(shù)據(jù),dd為寫入的地址,對(duì)于25045而言為000-1FF*/
void byte_write(aa,dd)
uchar aa;
uint dd;
{
uchar tmp;

wren_cmd();//寫使能子程序

SCK=0;
CS=0;
if(dd>0xff)
tmp =WRITE_INST | 0x08;
else
tmp = WRITE_INST;
outbyt(tmp);/* Send WRITE instruction including MSB of address */
/*將高位地址左移3位與寫入先導(dǎo)字相或,得到正確的先導(dǎo)字寫入25045*/
outbyt((uchar)(dd&0xff));
/*輸出低位地址到25045*/
outbyt(aa);
/*寫入數(shù)據(jù)到25045的對(duì)應(yīng)單元*/
SCK=0;
CS=1;
wip_poll();
/*檢測(cè)是否寫完*/

wrdi_cmd();//寫使能復(fù)位,其實(shí)這句可以省略，每寫一次就自動(dòng)復(fù)位
}



/*;***********************************************************************
*
;* Name: BYTE_READ
;* Description: Single Byte Read
;* Function: This routine sends the command to read a single byte from the EEPROM memory
array
;* Calls: outbyt, inputbyt
;* Input: None
;* Outputs: A = read byte
;* Register Usage: A, BXicor Application Note AN21
;*********************************************************************
*/
/*字節(jié)讀出,其中dd為讀出的地址,返回的值為讀出的數(shù)據(jù)*/
uchar byte_read(dd)
uint dd;
{
uchar cc,tmp;
SCK=0;
CS=0;
if(dd>0xff)
tmp =READ_INST | 0x08;
else
tmp = READ_INST;
outbyt(tmp);/* Send READ_INST instruction including MSB of address */
/*將高位地址左移3位與讀出先導(dǎo)字相或,得到正確的先導(dǎo)字寫入25045*/
outbyt((uchar)(dd&0xff));
/*輸出低位地址到25045*/
cc=inputbyt();/*得到讀出的數(shù)據(jù)*/
SCK=0;
CS=1;
return cc;
}


/*;**********************************************************************
*
;* Name: PAGE_WRITE
;* Description: Page Write
;* Function: This routine sends the command to write three consecutive bytes to the EEPROM
;* memory array using page mode
;* Calls: outbyt, wip_poll
;* Input: None
;* Outputs: None
;* Register Usage: A, B
;**************************************************************************
*/
/*頁(yè)面寫入,其中aa1,aa2,aa3,aa4為需要寫入的4個(gè)數(shù)據(jù)(最大也就只能一次寫入4個(gè)字,dd為寫入的首地址*/
void page_write(aa1,aa2,aa3,aa4,dd)
uchar aa1,aa2,aa3,aa4;
uint dd;
{
SCK=0;
CS=0;
outbyt((((uchar)(dd-0XFF))<<3)|WRITE_INST);// Send WRITE instruction including MSB of address
//將高位地址左移3位與寫入先導(dǎo)字相或,得到正確的先導(dǎo)字寫入25045
outbyt((uchar)(dd));
//寫入低位地址到25045
outbyt(aa1);
//寫入數(shù)據(jù)1到25045的對(duì)應(yīng)單元
outbyt(aa2);
//寫入數(shù)據(jù)2到25045的對(duì)應(yīng)單元
outbyt(aa3);
//寫入數(shù)據(jù)3到25045的對(duì)應(yīng)單元
outbyt(aa4);
//寫入數(shù)據(jù)4到25045的對(duì)應(yīng)單元
SCK=0;
CS=1;
wip_poll();
}




/*;**********************************************
*
;* Name: SEQU_READ
;* Description: Sequential Read
;* Function: This routine sends the command to read three consecutive bytes from the EEPROM
;* memory array using sequential mode
;* Calls: outbyt, inputbyt
;* Input: None
;* Outputs: A = last byte read
;* Register Usage: A, B
;************************************************************
*/
/*連續(xù)讀出,由于函數(shù)的返回值只能為1個(gè),對(duì)于連續(xù)讀出的數(shù)據(jù)只能使用指針作為函數(shù)的返回值才能做到返回一系列的數(shù)組*/
//sequ_read:
unsigned int *page_read(n,dd)
uchar n;//n是希望讀出的數(shù)據(jù)的個(gè)數(shù)，n<=11
unsigned int dd;//dd是讀出數(shù)據(jù)的首地址
{
uchar i;
uchar pp[10];
unsigned int *pt=pp;
SCK=0;
CS=0;
outbyt((((uchar)(dd-0XFF))<<3)|READ_INST);
for (i=0;i{
pp[i]=inputbyt();
}
return (pt);
}
/*調(diào)用的方法如下
unsigned int *p;
p=page_read(4,100);
a=*(p)
b=*(p+1)
c=*(p+2)
d=*(p+3)
//abcd中存放25045中由100地址開始的4個(gè)數(shù)據(jù)
*/
/* Send WRITE
mov DPTR, #PAGE_ADDR ; Set address of 1st byte to be read
clr sck ; Bring SCK low
clr cs ; Bring /CS low
mov A, #READ_INST
mov B, DPH
mov C, B.0
mov ACC.3, C
lcall outbyt ; Send READ instruction with MSB of address
mov A, DPL
lcall outbyt ; Send low order address byte
lcall inputbyt ; Read 1st data byte
lcall inputbyt ; Read 2nd data byte
lcall inputbyt ; Read 3rd data byte
clr sck ; Bring SCK low
setb cs ; Bring /CS high
ret*/




/*;*********************************************************************
*
;* Name: RST_WDOG
;* Description: Reset Watchdog Timer
;* Function: This routine resets the watchdog timer without sending a command
;* Calls: None
;* Input: None
;* Outputs: None
;* Register Usage: None
;***********************************************************************
*/
/*復(fù)位DOG*/
void rst_wdog (void)
{
CS=0;
CS=1;
}





/*;************************************************************************
*
;* Name: WIP_POLL
;* Description: Write-In-Progress Polling
;* Function: This routine polls for completion of a nonvolatile write cycle by examining the
;* WIP bit of the status register
;* Calls: rdsr_cmdXicor Application Note AN21
;* Input: None
;* Outputs: None
;* Register Usage: R1, A
;************************************************************************
*/
/*檢測(cè)寫入的過程是否結(jié)束*/
void wip_poll(void)
{
uchar aa;
uchar my_flag;
for (aa=0;aa{
my_flag=rdsr_cmd();
if ((my_flag&0x01)==0) {aa=MAX_POLL;}/*判斷是否WIP=0,即判斷是否寫入過程已經(jīng)結(jié)束,若結(jié)束就跳出,否則繼續(xù)等待直到達(dá)到最大記數(shù)值*/
}
//aa=1;
//while(aa){
//my_flag=rdsr_cmd();
//if ((my_flag&0x01)==0){
//aa=0;/*判斷是否WIP=0,即判斷是否寫入過程已經(jīng)結(jié)束,若結(jié)束就跳出,否則繼續(xù)等待直到達(dá)到最大記數(shù)值*/
//}
//}
aa = 0;
}




/*;**************************************************************************
*
;* Name: OUTBYT
;* Description: Sends byte to EEPROM
;* Function: This routine shifts out a byte, starting with the MSB, to the EEPROM
;* Calls: None
;* Input: A = byte to be sent
;* Outputs: None
;* Register Usage: R0, A
;***********************************************************************
*/
/*輸出一個(gè)數(shù)據(jù)到25045,此數(shù)據(jù)可能為地址,先導(dǎo)字,寫入的數(shù)據(jù)等*/
void outbyt(aa)
uchar aa;
{
uchar my_flag1,my_flag2,i;
my_flag1=aa;
for (i=0;i<8;i++)
{
my_flag2=my_flag1&0x80 ;
SI=my_flag2>>7;
delay(1);
SCK=0;
SCK=1; delay(3);
my_flag1 <<= 1 ;
}
SI=0;/*使SI處于確定的狀態(tài)*/
}






/*;***************************************************************************
*
;* Name: INPUTBYT
;* Description: Recieves byte from EEPROM
;* Function: This routine recieves a byte, MSB first, from the EEPROM
;* Calls: None
;* Input: None
;* Outputs: A = recieved byte
;* Register Usage: R0, A
;**********************************************************************
*/
/*得到一個(gè)數(shù)據(jù),此數(shù)據(jù)可能為狀態(tài)寄存器數(shù)據(jù),讀出的單元數(shù)據(jù)等*/
uchar inputbyt(void)
{
uchar aa,my_flag;
char i;
aa = 0;
for (i=7;i>=0;i--)
{
SCK=0;
//delay(1);
my_flag=SO;
SCK=1;

//delay(1);
my_flag <<= i;
aa |= my_flag ;
my_flag=0x00;
}
return aa;
}