关于IIC的地址问题

wanghongzhi1986

关于IIC的地址问题 [复制链接]

各位兄弟
请问IIC从设备的地址是怎么设置的？不是物理地址吧？是不是芯片自己定义的？
我这有个程序是关于2410通过IIC向AT24C02（EEPROM）中写数据和读取数据的
为什么这里面设置了两个从机地址？：：：
void Test_Iic2(void)
{
unsigned int i,j,save_E,save_PE;
static U8 data[256];

Uart_Printf("IIC Test(Polling) using AT24C02\n");

save_E  = rGPECON;
save_PE  = rGPEUP;
rGPEUP  ?= 0xc000;                //Pull-up disable
rGPECON &= ~0xf0000000;
rGPECON ?= 0xa0000000;             //GPE15:IICSDA , GPE14:IICSCL

//Enable ACK, Prescaler IICCLK=PCLK/16, Enable interrupt, Transmit clock value Tx //clock=IICCLK/16
rIICCON  = (1 < <7) ? (0 < <6) ? (1 < <5) ? (0xf); //0xaf

rIICADD  = 0x10;                   //2410 slave address = [7:1]
rIICSTAT = 0x10;                   //IIC bus data output enable(Rx/Tx)

Uart_Printf("Write test data into AT24C02\n");

  for(i=0;i <256;i++)
      _Wr24C080(0xa0,(U8)i,i);//void _Wr24C080(U32 slvAddr,U32 addr,U8 data)
for(i=0;i <256;i++)
      data = 0;

Uart_Printf("Read test data from AT24C02\n");
for(i=0;i <256;i++)
      _Rd24C080(0xa0,(U8)i,&(data));

for(i=0;i <8;i++)
{
      for(j=0;j <8;j++)
         Uart_Printf("%2x ",data[i*8+j]);
      Uart_Printf("\n");
}

Uart_Printf("OK! Write data is same to Read data!\n");
rGPEUP  = save_PE;
rGPECON = save_E;
}
void _Wr24C080(U32 slvAddr,U32 addr,U8 data)
{
_iicMode    = WRDATA;
_iicPt       = 0;
_iicData[0]  = (U8)addr;
_iicData[1]  = data;
_iicDataCount = 2;

rIICDS       = slvAddr;          //0xa0
   //Master Tx mode, Start(Write), IIC-bus data output enable
   //Bus arbitration sucessful, Address as slave status flag Cleared,
   //Address zero status flag cleared, Last received bit is 0
rIICSTAT    = 0xf0;
   //Clearing the pending bit isn't needed because the pending bit has been cleared.
while(_iicDataCount!=-1)
   Run_IicPoll();

_iicMode = POLLACK;

while(1)
{
      rIICDS = slvAddr;
      _iicStatus = 0x100;          //To check if _iicStatus is changed
      rIICSTAT  = 0xf0;             //Master Tx, Start, Output Enable, Sucessful, Cleared, Cleared, 0
      rIICCON = 0xe0;//0xaf;             //Resumes IIC operation. //hzh
      while(_iicStatus==0x100)
         Run_IicPoll();

      if(!(_iicStatus & 0x1))
         break;                   //When ACK is received
}
rIICSTAT = 0xd0;                   //Master Tx condition, Stop(Write), Output Enable
rIICCON  = 0xe0;//0xaf;                   //Resumes IIC operation. //hzh
Delay(1);                         //Wait until stop condtion is in effect.
   //Write is completed.
}

duibuqi

1、“IIC Test(Polling) using AT24C02” 那么 AT24C02 这个芯片有自己的IIC 地址也许是你这里的0XA0 吧
2、IIC标准中读写操作时通过地址字节的最末位来确认的， Bit 0 =0 代表IIC写 Bit 0 = 1 代表 IIC 读取At24C02操作，

详细请先看IIC协议标准和芯片资料的 IIC 部分讲解。