# include <stdio.h>
# include <reg52.h>
# define uchar unsigned char
# define uint unsigned int
 sbit SO=P1^1;/*25045輸出*/
 sbit SI=P1^2;/*25045輸入*/
 sbit SCK=P1^3;/*25045時鐘*/
 sbit CS=P1^4;/*25045片選*/
 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的先導字,應當為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字*/
 uchar code READ_INST=0X03;
 /* Read memory instruction (READ)*/
 /*讀出25045的先導字,應當為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字*/
 uint code BYTE_ADDR=0X55;
 /* Memory address for byte mode operations*/
 uchar code BYTE_DATA=0X11;
 /*Data byte for byte write operation*/
 uint  code PAGE_ADDR=0X1F;
 /* Memory address for page mode operations*/
 /*頁面寫入的其始地址*/
 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 STATUS_REG=0X20;
 /* Status register,設置DOG時間設置為200毫秒,無寫保護*/
 /*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,是寫保護設置位,00為無保護,01為保護180-1FF,10為保護100-1FF,11為保護000-1FF.第1位為WEL,
 當他為1時代表已經"寫使能"設置了,現(xiàn)在可以寫了,只讀位.第0位為WIP,當他為1時代表正在進行寫操作,是只讀*/
 uchar code  MAX_POLL=0x99;
 /* Maximum number of polls*/
 /*最大寫過程時間,確定25045的最大的寫入過程的時間*/
 uchar code INIT_STATE=0x09;
 /* Initialization value for control ports*/
 uint code SLIC=0x30;
 /* Address location of SLIC*/
 void wren_cmd(void);/*寫使能子程序*/
 void wrdi_cmd(void);/*寫使能復位*/ 
 void wrsr_cmd(void);/*復位時間位和數(shù)據(jù)保護位寫入狀態(tài)寄存器*/ 
 uchar rdsr_cmd(void);/*讀狀態(tài)寄存器*/
 void byte_write(uchar aa,uint dd);/*字節(jié)寫入,aa為寫入的數(shù)據(jù),dd為寫入的地址*/
 uchar byte_read(uint 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(uchar aa1,uchar aa2,uchar aa3,uchar aa4,uint dd);/*頁寫入*/
 void sequ_read(void);/*連續(xù)讀出*/ 
 void rst_wdog(void);/*DOG復位*/
 void outbyt(uchar aa);/*輸出一個字節(jié)到25045中，不包括先導字等*/
 uchar inputbyt();/*由25045輸入一個字節(jié)，不包括先導字等額外的東西*/ 
 void wip_poll(void);/*檢查寫入過程是否結束*/
 
 
/*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 */
 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 */
 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;
 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 */
 SCK=0;/* Bring SCK low */
 CS=1;/* Bring /CS high */
 wip_poll();/* Poll for completion of write cycle */
}





/*;*******************************************************************************************
*
;* 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,對于25045而言為000-1FF*/
void byte_write(aa,dd)
uchar aa;
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位與寫入先導字相或,得到正確的先導字寫入25045*/
 outbyt((uchar)(dd));
 /*輸出低位地址到25045*/
 outbyt(aa);
 /*寫入數(shù)據(jù)到25045的對應單元*/
 SCK=0;
 CS=1;
 wip_poll();
 /*檢測是否寫完*/
}



/*;*******************************************************************************************
*
;* 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;
 SCK=0;
 CS=0;
 outbyt((((uchar)(dd-0XFF))<<3)|READ_INST);/* Send READ_INST instruction including MSB of address */
 /*將高位地址左移3位與讀出先導字相或,得到正確的先導字寫入25045*/
 outbyt((uchar)(dd));
 /*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
;*******************************************************************************************
*/
/*頁面寫入,其中aa1,aa2,aa3,aa4為需要寫入的4個數(shù)據(jù)(最大也就只能一次寫入4個字,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位與寫入先導字相或,得到正確的先導字寫入25045*/
 outbyt((uchar)(dd));
 /*寫入低位地址到25045*/
 outbyt(aa1);
 /*寫入數(shù)據(jù)1到25045的對應單元*/
 outbyt(aa2);
 /*寫入數(shù)據(jù)2到25045的對應單元*/
 outbyt(aa3);
 /*寫入數(shù)據(jù)3到25045的對應單元*/
 outbyt(aa4);
 /*寫入數(shù)據(jù)4到25045的對應單元*/
 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,對于連續(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<n;i++)
 {
   pp[i]=inputbyt();
 }
 return (pt);
}
/*調用的方法如下*/
/*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
;*******************************************************************************************
*/
/*檢測寫入的過程是否結束*/
void wip_poll(void)
{
 uchar aa;
 uchar idata my_flag;
 for (aa=1;aa>MAX_POLL;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結束,若結束就跳出,否則繼續(xù)等待直到達到最大記數(shù)值*/
 }
}




/*;*******************************************************************************************
*
;* 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
;*******************************************************************************************
*/
/*輸出一個數(shù)據(jù)到25045,此數(shù)據(jù)可能為地址,先導字,寫入的數(shù)據(jù)等*/
void outbyt(aa)
uchar aa;
{
 uchar my_flag1,i;
 for (i=0;i>7;i++)
 {
   my_flag1=aa;
   SCK=0;
   SI=(my_flag1>>i);
   SCK=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;
 for (i=7;i<0;i--)
 {
   SCK=0;
   my_flag=(uchar)(SO);
   SCK=1;
   aa=(aa||(my_flag<<i));
   my_flag=0x00;
 }
 return aa;
}