#include "reg51.h"
#include "intrins.h"
#define X24C44_WRDS 0x80 //RESET WRITE ENABLE LATCH
#define X24C44_STO 0x81 //TRANSFERS FROM RAM TO EEPROM
#define X24C44_WRITE 0x83 //RAM WRITE
#define X24C44_WREN 0x84 //SET WRITE ENABLE LATCH
#define X24C44_RCL 0x85 //TRANSFERS FROM EEPROM TO RAM, RESETS WRITE ENABLE LATCH
#define X24C44_READ 0x86 //RAM READ</P><P>
//#define NOP() { _nop_(); _nop_(); _nop_(); _nop_(); _nop_(); }
//對從芯片而言
sbit SPI24C44_CS =P1^1;
sbit SPI24C44_SK =P1^0;
sbit SPI24C44_DI =P1^2;
sbit SPI24C44_DO =P1^3;
lag(unsigned int Time){while(Time--);}
void delayms(){ unsigned char i=255; while(i--);}
//寫一字節(jié)// SPI_SK上升沿數(shù)據(jù)有效 _/-
void SPI24C44_WriteByte(unsigned char dat)
{ unsigned char count; 
for(count=0;count<8;count++) 
{
dat<<=1; 
SPI24C44_DI=CY; NOP(); 
SPI24C44_SK=1; ///上升 
SPI24C44_SK=0; //開始上升 NOP(); 
}
}
//讀一字// SPI_SK上升沿數(shù)據(jù)有效 _/—
unsigned int SPI24C44_ReadWord()
{ unsigned char count; 
unsigned int dat=0;
for(count=0;count<16;count++)
{ 
dat<<=1; 
if(SPI24C44_DO) dat++; //為"０"讀出一個字 
SPI24C44_SK=1; 
SPI24C44_SK=0; 
NOP(); 
} return(dat);
}
//從24C44(EEPROM)里面讀取一字
//address: 0-15
unsigned int SPI24C44_Read(unsigned char address)
{ 
unsigned char temp; 
unsigned int dat;
SPI24C44_SK=0; 
NOP(); 
SPI24C44_CS=0; 
NOP(); 
SPI24C44_DI=0; 
NOP(); 
SPI24C44_DO=0; 
NOP();
SPI24C44_CS=1; 
SPI24C44_WriteByte(X24C44_RCL); 
//PERFORM A RECALL TO SET THE RECALL LATCH
SPI24C44_CS=0;
SPI24C44_CS=1; 
SPI24C44_WriteByte(X24C44_WREN);
//PERFORM A RECALL TO SET THE RECALL LATCH 
SPI24C44_CS=0;
address=address<<3; 
temp= X24C44_READ | address;
SPI24C44_CS=1; 
SPI24C44_WriteByte(temp); //Read Data from RAM Address
dat=SPI24C44_ReadWord(); 
SPI24C44_CS=0;
return(dat);}//向24C44里(EEPROM)寫一字
SPI24C44_Write(unsigned char address,unsigned int dat)
{ unsigned char temp; 
unsigned int moon; 
SPI24C44_SK=0; 
NOP(); 
SPI24C44_CS=0; 
NOP(); 
SPI24C44_DI=0; 
NOP(); 
SPI24C44_DO=0; 
NOP();
SPI24C44_CS=1; 
SPI24C44_WriteByte(X24C44_RCL); //PERFORM A RECALL TO SET THE RECALL LATCH 
SPI24C44_CS=0;
SPI24C44_CS=1; 
SPI24C44_WriteByte(X24C44_WREN); //PERFORM A RECALL TO SET THE RECALL LATCH 
SPI24C44_CS=0; 
address=address<<3; 
temp=X24C44_WRITE | address;
SPI24C44_CS=1; 
SPI24C44_WriteByte(temp); //WRITE(1AAAA011): Write Data into RAM Address AAAA 
SPI24C44_WriteByte( (unsigned char)(dat>>8) ); 
//send data 
SPI24C44_WriteByte( (unsigned char)dat ); 
//send data 
SPI24C44_CS=0;
SPI24C44_CS=1; 
SPI24C44_WriteByte(X24C44_STO ); 
//STO(1XXXX001):Store RAM Data in E2PROM 
SPI24C44_CS=0; 
SPI24C44_CS=1; 
SPI24C44_WriteByte(X24C44_WRDS ); 
//STO(1XXXX001):Store RAM Data in E2PROM 
SPI24C44_CS=0; 
lag(500); 
moon=SPI24C44_Read(address>>3); 
if(moon==dat) SystemError=0; 
else SystemError=1;}//非標準SPI口驅動，比較難調(diào)注意芯片與CPU接口??！呵呵 


*********************************************************************


include "reg51.h"
#include "intrins.h"
sbit X25_cs=P1^1;//片選接口
sbit X25_sk=P1^0;//時鐘接口
sbit X25_si=P1^2;//數(shù)據(jù)輸入接口
sbit X25_so=P1^3;//數(shù)據(jù)輸出接口
void Write_Byte(unsigned char IData)
{
unsigned char i;
for(i=0;i<8;i++)
{
X25_cs=0;
NOP();
X25_sk=0;
IData<<=1;
NOP();
X25_si=CY;
NOP();
X25_sk=1;
NOP();
}
}
unsigned char Read_Byte(unsigned char Adress)
{
unsigned char count,i;
Write_Byte(0x03);
Write_Byte(Adress);
for(i=0;i<8;i++)
{
X25_sk=1;
count<<=1;
X25_sk=0;
if(X25_so) count++;
}
X25_cs=1;
return(count);
}
void WREN()
{
Write_Byte(0x06);
NOP();
X25_cs=1;
}
unsigned char WriteInData(unsigned char Address,unsigned char DataByte)
{ unsigned char mark ;
WREN();
Write_Byte(0x02);
Write_Byte(Address);
Write_Byte(DataByte);
//NOP();
X25_cs=1;
lag(3000);
mark=Read_Byte(Address);
if(DataByte==mark) SystemError=0;
if(mark!=DataByte) SystemError=1;
// return(SystemError);
}
//雖然是一讀一寫，但是其中暗藏殺機，讓人很難調(diào)通。一定注意接口的位置！呵呵！不信你就按普通的SPI程序方法寫寫試試！