通过IIC协议读写EEPROM及仿真

#include <reg52.h> #include <intrins.h> sbit lcdrs=P2^0; sbit lcden=P2^1; sbit scl=P1^6; sbit sda=P1^7; sbit led=P1^0; unsigned char aa=0; void init(); void wdat(unsigned char); void wcmd(unsigned char); void delay5us(); void start(); void stop(); void unanswer(); void wbyte(unsigned char); unsigned char rbyte(); void ack(); unsigned char i='0'; void main() { init(); start();// 写 起始信号 wbyte(0xa0); //对器件寻址 并发送写信号 ack(); //等待回应 wbyte(0); // 写 字节地址 ack(); //等待回应 wbyte('a'); //写数据‘a’ ack(); stop(); //写字节结束 aa=0; while(aa<2); //等待2ms start(); //读 起始信号 wbyte(0xa0); //器件寻址 ack(); wbyte(0); //读 字节地址 ack(); start(); wbyte(0xa1); //器件寻址 并发送读信号 ack(); i=rbyte(); unanswer(); //非应答 stop(); wdat(i); while(1); } void init() { TMOD=0x01; TH0=(65535-1000)/256; TL0=(65535-1000)%256; EA=1; ET0=1; TR0=1; wcmd(0x38); wcmd(0x06); wcmd(0x0c); wcmd(0x80); } void wdat(unsigned char dat) { lcdrs=1; P0=dat; lcden=0; lcden=1; lcden=0; aa=0; while(aa<1); } void wcmd(unsigned char dat) { lcdrs=0; P0=dat; lcden=0; lcden=1; lcden=0; aa=0; while(aa<1); } void start() { sda=1; scl=1; delay5us(); sda=0; delay5us(); scl=0; } void stop() { sda=0; scl=1; delay5us(); sda=1; delay5us(); scl=0; } void wbyte(unsigned char dat) { unsigned char i=0; for(i=0;i<8;i++) { dat=dat<<1; sda=CY; scl=1; delay5us(); scl=0; } } unsigned char rbyte() { unsigned char i,k=0; bit j; sda=1; for(i=0;i<8;i++) { scl=1; delay5us(); j=sda; k=(k<<1)|(unsigned char)j; scl=0; } return k; } void delay5us() { _nop_();_nop_();_nop_();_nop_();_nop_(); } void ack() //等待回应,若无回应则点亮led { sda=1; led=0; scl=1; while(sda==1) {led=0; while(1);} scl=0; } void unanswer() { sda=1; scl=1; delay5us(); scl=0; } void timer0() interrupt 1 { TH0=(65535-1000)/256; TL0=(65535-1000)%256; aa++; }