EEPROM.rar_8051 eeprom_at24c_eeprom

/****************************************************** 本实验将往EEPROM的0存储地址中写入10个数据，然后按S5和S6 来显示分别显示它们，AT24C64的页写大小为32个字节，程序中用 Addr%32来判断是否到达页底。学者可以通过改变或者把写部份 注释掉来验证数据是否存入EEPROM *******************************************************/ #include "includes.h" sbit SDA = P2^0; sbit SCL = P2^1; sbit Key0 = P3^2; sbit Key1 = P3^3; void Start(); void Stop(); unsigned char Ack(); void ReAck(); void NoAck(); unsigned char SendOneByte(unsigned char dat); unsigned char ReceiveOneByte(unsigned char Respond); void WriteEEPROM(unsigned char *buff, unsigned int Addr, unsigned char Len); void ReadEEPROM(unsigned char *buff, unsigned int Addr, unsigned char Len); extern void Display(unsigned char Number); extern void SystemInit(); void main(void) { unsigned char WriteBuff[10]; unsigned char ReadBuff[10]; unsigned char i; unsigned char j; SystemInit(); Display(77); j = 0; for(i=0;i<10;i++) { WriteBuff[i] = i; ReadBuff[i] = 0; } //WriteEEPROM(WriteBuff, 0, 10); //ReadEEPROM(ReadBuff,0,10); P2 = 0x0f; while(1) { if(!Key0) { while(!Key0); if(j<sizeof(ReadBuff)) { j++; Display(ReadBuff[j]); } } if(!Key1) { while(!Key1); if(j>0) { j--; Display(ReadBuff[j]); } } } } void WriteEEPROM(unsigned char *buff, unsigned int Addr, unsigned char Len) { while(Len) { //发送启动 Start(); //发送设备从地址 SendOneByte(0xa0); //发送存储地址高8位 SendOneByte(Addr >> 8); //发送存储地址低8位 SendOneByte(Addr); while(Len) { //发送数据 SendOneByte(*buff); //数据指针加1 buff++; //长度减1 Len--; //地址指针加1 Addr++; //是否到达页底 if(Addr%32) { //发送停止 Stop(); break; } } } //发送停止 Stop(); } void ReadEEPROM(unsigned char *buff, unsigned int Addr, unsigned char Len) { //发送启动 Start(); //发送设备从地址 SendOneByte(0xa0); //发送存储地址的高8位 SendOneByte(Addr >> 8); //发送存储地址的低8位 SendOneByte(Addr); while(Len) { if(Len>1) *buff = ReceiveOneByte(true); else *buff = ReceiveOneByte(false); } //发送停止 Stop(); } void Start() { //SCL拉高 SCL = 1; _nop_();_nop_();_nop_();_nop_(); _nop_();_nop_();_nop_();_nop_(); //SDA产生下降沿 SDA = 0; _nop_();_nop_();_nop_();_nop_(); } void Stop() { //SCL拉高 SCL = 1; _nop_();_nop_();_nop_();_nop_(); _nop_();_nop_();_nop_();_nop_(); //SDA产生上升沿 SDA = 1; _nop_();_nop_();_nop_();_nop_(); } unsigned char Ack() { unsigned char ack; SCL = 1; _nop_();_nop_();_nop_();_nop_(); _nop_();_nop_();_nop_();_nop_(); if(SDA) ack = false; else ack = true; SCL = 0; _nop_();_nop_();_nop_();_nop_(); SDA = 0; return ack; } //发送一个0表示应答 void ReAck() { SDA = 0; _nop_();_nop_();_nop_();_nop_(); _nop_();_nop_();_nop_();_nop_(); SCL = 1; _nop_();_nop_();_nop_();_nop_(); _nop_();_nop_();_nop_();_nop_(); SCL = 0; } //发送一个1表示不应答 void NoAck() { SDA = 1; _nop_();_nop_();_nop_();_nop_(); _nop_();_nop_();_nop_();_nop_(); SCL = 1; _nop_();_nop_();_nop_();_nop_(); _nop_();_nop_();_nop_();_nop_(); SCL = 0; _nop_();_nop_();_nop_();_nop_(); SDA = 0; } unsigned char SendOneByte(unsigned char dat) { unsigned char i; for(i=0;i<8;i++) { if(dat & 0x01) SDA = 1; else SDA = 0; SCL = 1; _nop_();_nop_();_nop_();_nop_(); _nop_();_nop_();_nop_();_nop_(); SCL = 0; } SDA = 0; if(Ack() == true) return true; else return false; } unsigned char ReceiveOneByte(unsigned char Respond) { unsigned char i; unsigned char result; for(i=0;i<8;i++) { SCL = 1; _nop_();_nop_();_nop_();_nop_(); if(SDA) result = (result << 1) | 1; else result = (result << 1) | 0; _nop_();_nop_();_nop_();_nop_(); _nop_();_nop_();_nop_();_nop_(); SCL = 0; } SDA = 0; if(Respond) ReAck(); else NoAck(); return result; }