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51單片機(jī)-AT24C

作者： 時(shí)間：2016-12-02 來源：網(wǎng)絡(luò) 收藏
寫入EEPROM一個(gè)2，然后讀出，在數(shù)碼管上顯示出來: #include ＜reg52.h＞
#define uchar unsigned char
#define uint unsigned int
sbit SCL = P3^6;
sbit SDA = P3^7;
void delay()
{ ;; } //5us
void delay1(uchar x)
{
uchar a,b;
for(a=x;a＞0;a--)
for(b=100;b＞0;b--);
}
void Init(){
SCL = 1;
SDA = 1;
}
void start(){
SDA = 1;
delay();
SCL = 1;
delay();
SDA = 0;
delay();
}
void stop(){
SDA = 0;
delay();
SCL = 1;
delay();
SDA = 1;
delay();
}
void write(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()
{
uchar i,k;
SCL=0;
delay();
SDA=1;
delay();
for(i=0;i＜8;i++)
{
SCL=1;
delay();
k=(k＜＜1)|SDA; // 將SDA賦給K的每一位
SCL=0;
delay();
}
return k;
}
void response(){
int i;
SCL = 1; //在SCL為高電平期間，進(jìn)行應(yīng)答
delay();
while((SDA == 1) && (i ＜ 170))i++; //SCL釋放總線，等待從設(shè)備應(yīng)答，從設(shè)備會(huì)把SDA拉低
SCL = 0;
delay();
}
void At24c_Write(uchar address, uchar value){
start();
write(0xa0); //寫入設(shè)備地址
response();
write(address); //寫入首地址
response();
write(value); //寫入數(shù)據(jù)
response();
stop();
}
uchar At24c_Read(uchar address){
uchar value;
start();
write(0xa0); //偽寫，先寫入設(shè)備地址
response();
write(address); //再寫入要讀取數(shù)據(jù)的首地址
response();
start(); //再次
write(0xa1); //寫入要讀取數(shù)據(jù)的地址，方向?yàn)?
response();
value = read(); //讀取數(shù)據(jù)
stop();
return value;
}
void main(){
P1 = 0x0; // 位選，使最地位數(shù)碼管被選中
Init();
At24c_Write(23,0x5b); // 在EEPROM的23這個(gè)地址上寫數(shù)據(jù)0x5b
delay1(100); // 在寫和讀之間要多延時(shí)一會(huì)兒，否則器件處理不完
P2 = At24c_Read(23); // 讀取23地址的數(shù)據(jù)，也就是剛才寫入的數(shù)據(jù)
while(1);
}
掉電后數(shù)據(jù)不丟失，復(fù)位后，仍然從剛才掉電的數(shù)字開始往下顯示。從0"9
#include ＜reg52.h＞
#define uchar unsigned char
#define uint unsigned int
sbit SCL = P3^6;
sbit SDA = P3^7;
uchar temp, sum;
uint flag;
unsigned char code duan[]={
0x3F,0x06,0x5B,0x4F,0x66,0x6D,0x7D,0x07,0x7F,0x6F,
0x77,0x7C,0x39,0x5E,0x79,0x71};
void delay()
{ ;; } //5us
void delay1(uchar x)
{
uchar a,b;
for(a=x;a＞0;a--)
for(b=100;b＞0;b--);
}
void Init(){
SCL = 1;
SDA = 1;
}
void start(){
SDA = 1;
delay();
SCL = 1;
delay();
SDA = 0;
delay();
}
void stop(){
SDA = 0;
delay();
SCL = 1;
delay();
SDA = 1;
delay();

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