24CXX系列EEPROM 51单片机读写程序

#include <REG2051.H> #include <intrins.h> #include "24Cxx.h" #define _ACK_ 1 #define _NACK_ 0 unsigned char Mask = 0xFF; //////////////////////////////////////////////////////////////////////////////////////////////// //延时约x毫秒 void DelayMs(unsigned int x) { unsigned char j; unsigned int i; for(i=x;i>0;i--) for(j=250;j>0;j--) { _DELAY_ } } //////////////////////////////////////////////////////////////////////////////////////////////// // void Start() { SDA = SDA_H; T_SU_DAT SCL = SCL_H; T_SU_STA SDA = SDA_L; T_HD_STA SCL = SCL_L; // T_LOW } //////////////////////////////////////////////////////////////////////////////////////////////// // void Stop() { SCL = SCL_L; SDA = SDA_L; T_SU_DAT SCL = SCL_H; T_BUF SDA = SDA_H; T_BUF } //////////////////////////////////////////////////////////////////////////////////////////////// // bit CAck() { bit Resp; SCL = SCL_L; SDA = SDA_H; T_LOW //T_LOW > T_SU_DAT SCL = SCL_H; T_HIGH Resp = (bit)(SDA & (~SDA_L)); SCL = SCL_L; // T_LOW return ~Resp; //Return _ACK_(1) When ACK(SDA==0) } //////////////////////////////////////////////////////////////////////////////////////////////// // void Ack() { SCL = SCL_L; SDA = SDA_L; T_LOW //T_LOW > T_SU_DAT SCL = SCL_H; T_HIGH SCL = SCL_L; // T_LOW } //////////////////////////////////////////////////////////////////////////////////////////////// // void NAck() { SCL = SCL_L; SDA = SDA_H; T_LOW //T_LOW > T_SU_DAT SCL = SCL_H; T_HIGH SCL = SCL_L; // T_LOW } //////////////////////////////////////////////////////////////////////////////////////////////// // void SendByte(unsigned char Byte) { unsigned char i; SCL = SCL_L; for(i=0; i<8; i++) { SDA = ((Byte & 0x80) ? (SDA_H) : (SDA_L)); T_LOW //T_LOW > T_SU_DAT SCL = SCL_H; T_HIGH Byte <<= 1; SCL = SCL_L; } // T_LOW } //////////////////////////////////////////////////////////////////////////////////////////////// // unsigned char ReceiveByte() { unsigned char Byte = 0, i; SCL = SCL_L; SDA = SDA_H; for(i=0; i<8; i++) { T_LOW //T_LOW > T_SU_DAT SCL = SCL_H; T_HIGH Byte <<= 1; Byte |= (bit)(SDA & (~SDA_L)); SCL = SCL_L; } // T_LOW return Byte; } //////////////////////////////////////////////////////////////////////////////////////////////// //////////////////////////////////////////////////////////////////////////////////////////////// // bit WR24Cxx( unsigned char* Buff, //缓冲区首地址 unsigned int NByte, //要写入的字节数 unsigned char DevAddr, //器件地址，对应器件地址引脚 unsigned int WordAddr, //片内首地址，字节地址 bit WR, //读写标志，实参为宏_WRITE_或_READ_ unsigned char Bus, //选用的总线通道，实参为宏_CHx_，可并联 unsigned char Device ) //器件类型，实参为宏_24Cxx_ { code unsigned char PageSize[10] = {8, 8, 16, 16, 16, 32, 32, 64, 64, 128};//各类型器件的页大小 unsigned char i; Mask = ~Bus; if(_WRITE_ == WR) //Write Operation { while(NByte > 0) { //Generate Control Word,For 24C01~16,Mingle Device Address with Page Addess switch(Device) { case _24C04_ : DevAddr &= 0xFC; DevAddr |= (unsigned char)(0x02 & (WordAddr >> 7)); break; case _24C08_ : DevAddr &= 0xF8; DevAddr |= (unsigned char)(0x06 & (WordAddr >> 7)); break; case _24C16_: DevAddr &= 0xF0; DevAddr |= (unsigned char)(0x0E & (WordAddr >> 7)); break; } //Dummy Write DevAddr &= 0xFE; //Write Start(); SendByte(DevAddr); //Control Byte if(_NACK_ == CAck()) { return FAIL; } if(Device > _24C16_) { SendByte((unsigned char)(WordAddr >> 8)); //High Address Byte if(_NACK_ == CAck()) { return FAIL; } } SendByte((unsigned char)(0x00FF & WordAddr)); //Low Address Byte if(_NACK_ == CAck()) { return FAIL; } //Write N Bytes if(0 == (WordAddr%(PageSize[Device]))) //Snap to page boundary { if(NByte > PageSize[Device]) { //Write One Page for(i=PageSize[Device]; i>0; i--) { SendByte(*(Buff++)); if(_NACK_ == CAck()) { return FAIL; } } NByte -= PageSize[Device]; WordAddr += PageSize[Device]; } else { //Write the Rest for(; NByte>0; NByte--) { SendByte(*(Buff++)); if(_NACK_ == CAck()) { return FAIL; } } } } else //Do not snap to page boundary { i=((PageSize[Device])-(WordAddr%(PageSize[Device]))); if(i > NByte) { i = NByte; } for(; i>0; i--) { SendByte(*(Buff++)); if(_NACK_ == CAck()) { return FAIL; } NByte--; WordAddr++; } } Stop(); DelayMs(T_WR); //Wait for Internal Write Cycle } return SUCCESS; //Finish Writing } else //Read Operation { //Generate Control Word,For 24C01~16,Mingle Device Address with Page Addess switch(Device) { case _24C04_ : DevAddr &= 0xFC; DevAddr |= (unsigned char)(0x02 & (WordAddr >> 7)); break; case _24C08_ : DevAddr &= 0xF8; DevAddr |= (unsigned char)(0x06 & (WordAddr >> 7)); break; case _24C16_: DevAddr &= 0xF0; DevAddr |= (unsigned char)(0x0E & (WordAddr >> 7)); break; } //Dummy Write DevAddr &= 0xFE; //Write Start(); SendByte(DevAddr); //Control Byte if(_NACK_ == CAck()) { return FAIL; } if(Device > _24C16_) { SendByte((unsigned char)(WordAddr >> 8)); //High Address Byte if(_NACK_ == CAck()) { return FAIL; } } SendByte((unsigned char)(0x00FF & WordAddr)); //Low Address Byte if(_NACK_ == CAck()) { return FAIL; } //Read N Bytes DevAddr |= 0x01; Start(); SendByte(DevAddr); //Control Byte if(_NACK_ == CAck()) { return FAIL; } while(NByte > 0) //Receive N Bytes { *(Buff++) = ReceiveByte(); NByte--; if(NByte > 0) { Ack(); } } NAck(); Stop(); return SUCCESS; //Finish Reading } }