2019年03月18日 | s3c2440A操作24C08

我这里实现的是非中断模式下的IIC操作

数据手册和代码对照着很容易看懂，尤其是数据手册上IIC那一章的几张程序流程图，一目了然。

下面是代码：

//这里没有用精确延时

void delay1()

{

int i = 0;

int j = 0;

for(i = 0; i < 100; i++)

{

for(j = 0; j < 100; j++);

}

}

/*************************************************************

Function name: IIC_Init

Description: Initialize IIC registers

Parameters: None

Returns: None

**************************************************************/

void IIC_Init()

{

//GPE14:IICSCL  GPE15:IICSDA

rGPECON = rGPECON & (~(0xf << 28)) | (0xa << 28);

//GPE14 GPE15 poll up function disabled

rGPEUP = 0xc000;

//rIICCON[7] = 1: enable IIC_bus acknowledge bit

//rIICCON[6] = 0: IICCLK = fPCLK / 16

//rIICCON[5] = 1: Tx/Rx interrupt enable

//rIICCON[3..0]: Tx clock = IICCLK/(IICCON[3:0]+1)

rIICCON = (1 << 7) | (0 << 6) | (1 << 5) | 0x0f;

//rIICSTAT[4] = 1: enable Rx/Tx

rIICSTAT = (1 << 4);

rIICADD = 0x10;

}

/*************************************************************

Function name: Write24C08_nbyte

Description: Write data to 24C08

Parameters: slave_addr: the address of IIC device, often set to "0xa0"

IIC_addr: exact data address

IIC_data: value of data

Returns: None

**************************************************************/

void Write24C08_nbyte(unsigned int slave_addr, unsigned int IIC_addr, unsigned char IIC_data)

{

  unsigned int i = 0;

unsigned int j = 0;

rIICDS = slave_addr;  //从设备地址

//rIICSTAT[7:6]:11--master Tx mode

//rIICSTAT[5]: 1--start signal

//rIICSTAT[4]: 1--enable Rx/Tx

rIICSTAT = 0xf0;  //开始写

while(!(rIICCON & 0x10));  //等待应答信号，该位为1，收到应答

rIICDS = IIC_addr; //向移位寄存器送数据：数据地址

for(i = 0; i < 10; i++);

rIICCON = 0xaf;

while(!(rIICCON & 0x10));

rIICDS = IIC_data;   //向移位寄存器送数据

rIICCON = 0xaf;   //rIICCON[4] = 0:清空挂起位

while(!(rIICCON & 0x10));

Uart_Printf("Send %d data %d to IIC\n", IIC_addr, IIC_data);

rIICSTAT = 0xd0; //rIICSTAT[5] = 0:STOP signal generation when write,停止信号

rIICCON = 0xaf; //清空挂起位

for(i = 0; i < 10; i++);

}

/*************************************************************

Function name: Read24C08_nbyte

Description: Read data from 24C08

Parameters: slave_addr: the address of IIC device, often set to "0xa0"

IIC_addr: exact data address

databuffer: used to storage data value

Returns: None

**************************************************************/

void Read24C08_nbyte(U32 slave_addr,U32 IIC_addr,U8 *databuffer)

{

        unsigned int i = 0;

unsigned int j = 0;

unsigned int add_in = IIC_addr;

        U32 temp = 0;

U32 tt = 0;

        rIICDS   = slave_addr;//0xa0

        rIICSTAT = 0xf0;    //开启IIC写功能，写IIC地址

while(!(rIICCON & 0x10));

        rIICDS   = (U8)add_in;   //数据具体地址

        for(i=0;i<10;i++);

        rIICCON  = 0xaf; //清空挂起标志位resumes IIC operation.

        while(!(rIICCON & 0x10))；

rIICDS   = slave_addr;

        rIICSTAT = 0xb0;      //bit[7:6]：10--master Rx mode，master receive mode

        rIICCON  = 0xaf;

        while(!(rIICCON & 0x10));

temp = rIICDS;

      rIICCON  = 0x2f;

  for(i=0;i<10;i++);

while(!(rIICCON & 0x10));

    tt = rIICDS;

Uart_Printf("databuffer = 0x%x, %d  IIC_addr = %d, temp = %d\n", tt, tt, IIC_addr, temp);  

        rIICSTAT = 0x90;      //停止读

        rIICCON  = 0xaf;

        delay1();

}