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发表于 2010-9-12 20:18:01
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AT24C01-AT24C256通用源程序（C51） 收藏
据说是AT24C01-AT24C256通用源程序，但按照我的经验，这个源程序仅适合AT24C04-AT24C256。
/*Sample:
/*main(){ ...
/* ReadMem(l,x,y); /*读。l为本次访问的器件号，在宏定义时分配不同芯片的不同
器件号，
x为本次欲读出的字节数；y为本次读数的起始地址*/
/* ...
/* WriteMem(l,x,y); /*写。l为本次访问的器件号，在宏定义时分配不同芯片不同
的器件号，
x为本次欲写入的字节数；y为本次写数的起始地址，
注：当心页写入的地址规律，即页地址在同一页内滚动;否则会出现页溢出*/
/*}*/
#define Wait_1us {_nop_();_nop_();}
#define Wait_2us {Wait_1us;Wait_1us;}
#define Sla_Wr 0xa0 /*0000 0 0 0 0*/
#define Sla_Rd 0xa1 /*0000 0 0 0 1*/
#define AT24C01 0x01
#define AT24C01A 0x02
#define AT24C02 0x03
#define AT24C04 0x04
#define AT24C08 0x05
#define AT24C16 0x06
#define AT24C32 0x07
#define AT24C64 0x08
#define AT24C128 0x09
#define AT24C256 0x0a
#define AT24C512 0x0b
#define Mem_Size AT24C256 // 01/01A/02/04/08/16/32/64/128/256/512
#define Chip_1 0x00 //本器件的器件地址，可以第一8个不同地址的芯片使之能用同一段程序进行读写
sbit bSda =P3^7;
sbit bScl =P3^6;
bit bScan_Err;
unsigned char idata cShare_Buf[8]={0,1,2,3,4,5,6,7}; //I2c read and write buffer
void Start_I2c(void);
void End_I2c(void);
unsigned char Scan_I2c();
void Send_I2c(unsigned char cData);
void Send_Ack(void);
void Send_Not_Ack(void);
void Write_Mem(unsigned char cMem_Size,cChips_Address,cData_Size,unsigned int
cStart_Address);
void Read_Mem(unsigned char cMem_Size,cChips_Address,cData_Size,unsigned int
cStart_Address);
/************Name:ScanI2c***********
Function:read 1byte from 24C01/512
NO.:1
Run time:79us 1=4+2us 0=5+1us f=111kbps/83.3Kbps
**********Function Start************/
void Start_I2c(void)
{
unsigned char /*idata*/ i;
bSda=bScl=1;
for(i=0;i<2;i++); //wait 7us
bSda=0;
for(i=0;i<2;i++); //wait 7us
bScl=0;
}
/**********Function End*************/
/************Name:ScanI2c***********
Function:read 1byte from 24C01/512
NO.:1
Run time:79us 1=4+2us 0=5+1us f=111kbps/83.3Kbps
**********Function Start************/
void End_I2c(void)
{
unsigned char /*idata*/ i;
bSda=0;
bScl=1;
for(i=0;i<2;i++); //wait 7us
bSda=1;
}
/**********Function End*************/
/************Name:ScanI2c***********
Function:read 1byte from 24C01/512
NO.:1
Run time:79us 1=3/5us 0=1/5us f=250/100kbps
**********Function Start************/
unsigned char Scan_I2c()
{
unsigned char /*idata*/ i,j;//IIC data
bSda=1;
j=0;
for(i=0;i<8;i++)
{
bScl=1;
j<<=1;
Wait_2us;
j|=bSda;
//Scan 0 Scan 1
bScl=0;
Wait_2us;
Wait_2us;
}
return j;
}
/**********Function End*************/
/************Name:SendI2c***********
Function:Send 1byte to 24C01/512
NO.:2
Run time:82us 1=1/3us 0=3us f=250/100kbps
**********Function Start************/
void Send_I2c(unsigned char cData)
{
unsigned char /*idata*/ i;
for(i=0;i<8;i++)
{
bSda=(bit)(cData&0x80);
bScl=1;
cData<<=1;
Wait_2us;
Wait_2us;
bScl=0;
Wait_2us;
}
bSda=bScl=1; //检测ACK
for(i=0;(bSda==1)&&(bScan_Err==0);i++)
{
if(i==30)
bScan_Err=1; //如果101us没有响应就错误
}
bScl=0;
}
/**********Function End************/
/************Name:SendAck***********
Function:Send ack
NO.:3
Run time:10us+4us
**********Function Start************/
void Send_Ack(void)
{
unsigned char /*idata*/ i;
bSda=0;
bScl=1;
for(i=0;i<2;i++); //wait 8us
bScl=0;
bSda=1;
}
/**********Function End*************/
/************Name:SendNotAck***********
Function:send not ack
NO.:4
Run time:10us+4us
**********Function Start************/
void Send_Not_Ack(void)
{
unsigned char /*idata*/ i;
bScl=bSda=1;
for(i=0;i<2;i++); //wait 8us
bScl=0;
}
/**********Function End*************/
/************Name:WriteMem***********
Function:write data to 24C01/512
NO.:5
Run time:80us(1byte)*cData_Size+
**********Function Start************/
void Write_Mem(unsigned char cMem_Size,cChips_Address,cData_Size,unsigned int cStart_Address)
{
unsigned char /*idata*/ i,cAddress[2]; //0-L;1-H
bScan_Err=0;
cAddress[0]=cStart_Address;
cStart_Address>>=8;
cAddress[1]=cStart_Address;
i=Sla_Wr;
i|=cChips_Address;
if(cMem_Size==AT24C256)
i&=0xf7;
Start_I2c();
Send_I2c(i); //SLA:1010 xxx0
if(cMem_Size==AT24C256) //1-16用1个字节地址，32-512用2个字节地址，匹配地址AT24C32、64
Send_I2c(cAddress[1]); //先发送高字节地址
Send_I2c(cAddress[0]); //如果是双字节地址则为低地址否则为高地址
for(i=0;(bScan_Err==0)&&(i!=cData_Size);i++)
Send_I2c(cShare_Buf); //写一个字节数据
End_I2c();
}
/**********Function End*************/
/************Name:ReadMem***********
Function:Read data from 24C01/512
NO.:6
Run time:80us(1byte)*cData_Size+
**********Function Start************/
void Read_Mem(unsigned char cMem_Size,cChips_Address,cData_Size,unsigned int cStart_Address)
{
unsigned char /*idata*/ i,cAddress[2];
bScan_Err=0;
cAddress[0]=cStart_Address; //将16位地址分解为高低字节
cStart_Address>>=8;
cAddress[1]=cStart_Address;
i=Sla_Wr;
i|=cChips_Address;
if(cMem_Size==AT24C256)
i&=0xf7;
Start_I2c();
Send_I2c(i);//SLA:1010 xxx0
if(cMem_Size==AT24C256) //1-16用1个字节地址，32-512用2个字节地址，匹配地址AT24C32、64
Send_I2c(cAddress[1]); //先发送高字节地址
Send_I2c(cAddress[0]); //address and write
i|=0x01; //Read
Start_I2c();
Send_I2c(i); //address and read
for(i=0;(bScan_Err==0)&&(i!=cData_Size);i++)
{
cShare_Buf=Scan_I2c(); //读入第一个字节
if(i==(cData_Size-1))
Send_Not_Ack();
else
Send_Ack();
}
End_I2c();
}
/**********Function End*************/ |
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发表于 2010-9-8 12:55:07
