基于AVR单片机的AT24C01-512eeprom读写程序

 

#define SDA1() PORTC|=1< #define SDA0() PORTC&=~(1< #define SDAout() DDRC|=1< #define SDAin() DDRC&=~(1< #define RSDA() PINC&(1< #define SCL1() PORTC|=1< #define SCL0() PORTC&=~(1< #define e2ptime 20

 

//起始
void WriteStart(void)
 {
  SDA1();
    Delay(e2ptime);//该函数为软件延时函数，根据需要自己去写吧
  SCL1();
    Delay(e2ptime);
  SDA0();
    Delay(e2ptime);
  SCL0();
 }

AT24C32 为4096字节(0x000-0xfff)
AT24C64 为8192字节(0x0000-0x1fff)
AT24C128 为16384字节(0x00-0x7ff)
AT24C256 容量为32768字节（0x0000-0x7fff）
AT24C512 容量为65536字节（0x0000-0xffff）
*/
 //写入数据，器件型号model，器件地址DevAddr，开始地址addr,数据*P_data，数据长度num
void AT24CxxWrite(unsigned int model,unsigned char DevAddr,unsigned int addr,unsigned char *P_data,unsigned char num)
 {
 unsigned char i,temp,*p,ICerror=0,page_size;
 unsigned long next_page_start_addr;
 if(model<2)page_size=8;
 else if(model<32)page_size=16;
   else if(model<128)page_size=32;
     else if(model<512)page_size=64;
       else page_size=128;
 next_page_start_addr=model;
 next_page_start_addr<<=7;//总容量
 while(next_page_start_addr)
 {
  next_page_start_addr-=page_size;
  if(next_page_start_addr<=addr){next_page_start_addr+=page_size;break;}
 }
 
Wagain:
 p=P_data;
 i=num;//数据个数
 if(ICerror<10)ICerror++;
 else goto Wstop;
 SDAout();
 WriteStart();      //启动
 temp=0xa0+(DevAddr<<1);
 if(model<16) temp+=((addr>>7)&0x0e);//器件24c32以下地址高位
 if(WriteByte(temp))   //头字节
 goto Wagain;
 if(model>16)//写器件24c32以上地址高位
 {
  if(WriteByte(addr>>8))//
  goto Wagain;
 }
 if(WriteByte(addr&0xff)) //写地址低位
 goto Wagain;
 while(i)//写入数据i个
 {
  i--;
  if(WriteByte(*(p++)))goto Wagain;
  addr++;
  if(addr==next_page_start_addr)break;
 }
Wstop:
 Stop();
 if(i)//写到了页末，重新开始写新一页
 { 
 Delay(100);
 num=i;
 P_data=p;
 next_page_start_addr+=page_size;
 if(addr==model*128){addr=0;next_page_start_addr=page_size;}
 goto Wagain;
 }
}
//读数据，器件型号model，器件地址DevAddr，地址addr,存放到 *P_data，数据长度num
unsigned char AT24CxxRead(unsigned int model,unsigned char DevAddr,unsigned int addr,unsigned char *P_data,unsigned char num)
{
 unsigned char temp,*p,ICerror=0;
Ragain:
 if(ICerror<10)ICerror++;
 else goto Rstop;
 SDAout();
 p=P_data;
 WriteStart();//
 temp=0xa0+(DevAddr<<1);
 if(model<16) temp+=((addr>>7)&0x0e);//器件24c32以下地址高位
 if(WriteByte(temp))//;//头字节
 goto Ragain;
 if(model>16)//器件24c32以上地址高位
 {
  if(WriteByte(addr>>8))//
  goto Ragain;
 }
 if(WriteByte(addr&0xff))//
 goto Ragain;
Ragain2:
 WriteStart();//
 if(WriteByte(temp|1))//
 goto Ragain2;
 while(num--)
 {
  *(p++)=ReadByte();//
  if(num)WACK(0);
  else WACK(1);
 }
 Rstop:
 Stop();//
 return(ICerror);
}

 

main()

{

unsigned char card[20],addr,temp;

……

   AT24CxxWrite(256,3,addr,&Card[0],12);//at24c256,a1,a0引脚都的接高电平，片内地址为addr为起始地址，从数组card[]中取12字节数据存到存储器中
  temp= AT24CxxRead(256,3,addr,&Card[0],12);//at24c256,a1,a0引脚都的接高电平，片内地址为addr为起始地址，从存储器中取数到数组card[]中。返回读操作是否出错信息到temp。