读写25LC040的问题

chenbingjy

读写25LC040的问题 [复制链接]

proteus仿真图：

程序：

#include <reg51.h> // ??8051?????  
#include <intrins.h>

#define uchar unsigned char
#define uint  unsigned int
	
sbit SCK=P2^0;
sbit SI=P2^1;
sbit SO=P2^2;
sbit CS=P2^3;
// ???SPI??????  
void SPI_Init(void); // SPI???  
void SPI_SendByte(unsigned char byte); // SPI??????  
unsigned char SPI_ReceiveByte(void); // SPI??????  
void SPI_CS_Low(void); // ??????  
void SPI_CS_High(void); // ??????  
 
unsigned char readData,readData1,readData2;
// 25LC040???  
#define READ_INSTRUCTION  0x03 // ???(??25LC040,????????????)  
#define WRITE_INSTRUCTION 0x02 // ???(??,??????????)  
#define WREN_INSTRUCTION  0x06 // ?????  
  
// ????  
void EEPROM_WriteByte(unsigned char address, unsigned char date) {  
    SPI_CS_Low(); // ??????  
    SPI_SendByte(WREN_INSTRUCTION); // ???????  
    SPI_CS_High(); // ??????,???????(??????)  
      
    SPI_CS_Low(); // ????????  
    SPI_SendByte(WRITE_INSTRUCTION); // ?????  
    //SPI_SendByte((address >> 8) & 0xFF); // ???????(??25LC040,?????)  
    SPI_SendByte(address); // ???????  
    SPI_SendByte(date); // ????  
    SPI_CS_High(); // ??????,?????  
      
    // ???????????,?????EEPROM????  
}  
  
unsigned char EEPROM_ReadByte(unsigned char address) {  
    unsigned char date;  
      
    SPI_CS_Low(); // ??????  
    SPI_SendByte(READ_INSTRUCTION); // ?????  
    //SPI_SendByte((address >> 8) & 0xFF); // ???????(??25LC040,?????)  
    SPI_SendByte(address ); // ???????  
    date = SPI_ReceiveByte(); // ????  
    SPI_CS_High(); // ??????,?????  
      
    return date;  
}  

void EEPROM_ReadByte1(unsigned char address) {  
    unsigned char date;  
      
    SPI_CS_Low(); // ??????  
    SPI_SendByte(READ_INSTRUCTION); // ?????  
    //SPI_SendByte((address >> 8) & 0xFF); // ???????(??25LC040,?????)  
    SPI_SendByte(address ); // ???????  
    readData = SPI_ReceiveByte(); // ????
		readData1 = SPI_ReceiveByte();
	 readData2 = SPI_ReceiveByte();
    SPI_CS_High(); // ??????,?????  
      
   // return date;  
}  
  
void main(void) { 
		uint i;
		
    SPI_Init(); // ???SPI??  
      
    // ??:?????EEPROM  
    EEPROM_WriteByte(0x00, 0xAB); // ???0x0000??0xAB
		for(i=0;i<10000;i++);
    EEPROM_WriteByte(0x01, 0x55); // ???0x0000??0xAB
		for(i=0;i<10000;i++);
		EEPROM_WriteByte(0x02, 0x66); // ???0x0000??0xAB
		for(i=0;i<10000;i++);
    // ??:?EEPROM????  
    EEPROM_ReadByte1(0); // ???0x0000????  
    P1=  readData;
	_nop_();
			_nop_();
		//readData1 = EEPROM_ReadByte(0x01); // ???0x0000????  
    P3=  readData1;
	_nop_();
			_nop_();
		//readData2 = EEPROM_ReadByte(0x02); // ???0x0000????  
    P0=  readData2;
    // ?????????????????  
      
    while (1) {  
        // ???  
    }  
}  
  
// ????????SPI???????  
void SPI_Init(void) {  
    // ???SPI??,????????  
}  
  
void SPI_SendByte(unsigned char byte) {  
    // ??SPI??????
		uchar i;
		for(i=0;i<8;i++)
		{
			SCK=0;
			_nop_();
			_nop_();
			if((byte&0x80)==0x80)
				SI=1;
			else
				SI=0;
			_nop_();
			_nop_();
			byte<<=1;
			SCK=1;
			_nop_();
			_nop_();
		}
}  
  
unsigned char SPI_ReceiveByte(void) {  
    // ??SPI??????  
		uchar i,dat=0;
	for(i;i<8;i++)
	{
		dat<<=1;
		SCK=1;			//第一位
		_nop_();
			_nop_();
	SCK=0;
		_nop_();
			_nop_();
		SO=1;
		if(SO)
			dat|=1;
		
		_nop_();
			_nop_();
		
	}
		
		
    return dat; // ??????????????  
}  
  
void SPI_CS_Low(void) {  
    // ???????  
    CS = 0; // ?????????P1.0??  
}  
  
void SPI_CS_High(void) {  
    // ???????  
    CS = 1; // ?????????P1.0??  
}

只有第一次读的是对的。

请问高手，哪里错了？谢谢