| //EEPROM程序，AT24CXX，适用于51单片机 //***it sda=P2^0; //***it scl=P2^1; void delay() { unsigned char shu; for(shu=2;shu>0;shu--); } void start() //开始信号 { sda=1; delay(); scl=1; delay(); sda=0; delay(); } void stop() //停止 { sda=0; delay(); scl=1; delay(); sda=1; delay(); } void respons() //应答 { uchar i; scl=1; delay(); while((sda==1)&&(i<250))i++; scl=0; delay(); } void write_byte(uchar date) { uchar i,temp; temp=date; for(i=0;i<8;i++) { temp=temp<<1; scl=0; delay(); sda=CY; delay(); scl=1; delay(); } scl=0; delay(); sda=1; delay(); } uchar read_byte() { uchar i,k; scl=0; delay(); sda=1; delay(); for(i=0;i<8;i++) { scl=1; delay(); k=(k<<1)|sda; scl=0; delay(); } return k; } void delay1(uchar x) { uchar a,b; for(a=x;a>0;a--) for(b=100;b>0;b--); } void write_add(uchar address,uchar date) { start(); write_byte(0xa0); respons(); write_byte(address); respons(); write_byte(date); respons(); stop(); } uchar read_add(uchar address) { uchar date; start(); write_byte(0xa0); respons(); write_byte(address); respons(); start(); write_byte(0xa1); respons(); date=read_byte(); stop(); return date; } |
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