iic.c

ARM S3C2410处理器 iic总线驱动程序 开发环境：ads1.2

              
            rIICCON = 0xaf;                     //resumes IIC operation.
            break;

        case SETRDADDR:
            if((_iicDataCount--)==0)
                break;                          //IIC operation is stopped because of IICCON[4]    
            rIICDS = _iicData[_iicPt++];
            for(i=0;i<10;i++);                  //For setup time until rising edge of IICSCL
            rIICCON = 0xaf;                     //Resumes IIC operation.
            break;

        default:
            break;      
    }
}


//===================================================================
//       SMDK2410 IIC configuration
//  GPE15=IICSDA, GPE14=IICSCL
//  "Non-Interrupt" mode for IIC block
//=================================================================== 
/*
*********************************************************
* 函数介绍：本函数是测试iic没有使用中断的程序。				
* 输入参数：无
* 输出参数：无
* 返回值  ：无
*********************************************************
*/
void Test_Iic2(void)
{
    unsigned int i,j,save_E,save_PE;
    static U8 data[256];
    
    Uart_Printf("[ IIC Test(Polling) using KS24C080 ]\n");

    save_E   = rGPECON;
    save_PE  = rGPEUP;

    rGPEUP  |= 0xc000;                  //Pull-up disable
    rGPECON |= 0xa00000;                //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);

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

    Uart_Printf("Write test data into KS24C080\n");

    for(i=0;i<256;i++)
        _Wr24C080(0xa0,(U8)i,255-i);
    for(i=0;i<256;i++)
        data[i] = 0;

    Uart_Printf("Read test data from KS24C080\n");
    for(i=0;i<256;i++)
        _Rd24C080(0xa0,(U8)i,&(data[i])); 

    for(i=0;i<16;i++)
    {
        for(j=0;j<16;j++)
            Uart_Printf("%2x ",data[i*16+j]);
        Uart_Printf("\n");
    }
    
    rGPEUP  = save_PE;
    rGPECON = save_E;
}

/*
*********************************************************
* 函数介绍：本函数是iic写程序，将数据写入KS24C080（IIC EEPROM）。				
* 输入参数：slvAddr--基地址（0XA0）
*           addr--地址偏移量
*           data--写入的数据
* 输出参数：无
* 返回值  ：无
*********************************************************
*/
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    = 0xaf;              //Resumes IIC operation. 
        while(_iicStatus==0x100)  
            Run_IicPoll();
              
        if(!(_iicStatus & 0x1))
            break;                      //When ACK is received
    }
    rIICSTAT = 0xd0;                    //Master Tx condition, Stop(Write), Output Enable
    rIICCON  = 0xaf;                    //Resumes IIC operation. 
    Delay(1);                           //Wait until stop condtion is in effect.
      //Write is completed.
}
        
/*
*********************************************************
* 函数介绍：本函数是iic读程序，将数据从KS24C080（IIC EEPROM）读出。				
* 输入参数：slvAddr--基地址（0XA0）
*           addr--地址偏移量
*           *data--读出数据放入的BUF的首地址
* 输出参数：无
* 返回值  ：无
*********************************************************
*/
void _Rd24C080(U32 slvAddr,U32 addr,U8 *data)
{
    _iicMode      = SETRDADDR;
    _iicPt        = 0;
    _iicData[0]   = (U8)addr;
    _iicDataCount = 1;

    rIICDS   = slvAddr;
    rIICSTAT = 0xf0;                    //MasTx,Start  
      //Clearing the pending bit isn't needed because the pending bit has been cleared.
    while(_iicDataCount!=-1)
        Run_IicPoll();

    _iicMode      = RDDATA;
    _iicPt        = 0;
    _iicDataCount = 1;
    
    rIICDS   = slvAddr;
    rIICSTAT = 0xb0;                    //Master Rx,Start
    rIICCON  = 0xaf;                    //Resumes IIC operation.   
    while(_iicDataCount!=-1)
        Run_IicPoll();

    *data = _iicData[1];
}

/*
*********************************************************
* 函数介绍：本函数是调用iic POLL的程序。				
* 输入参数：无
* 输出参数：无
* 返回值  ：无
*********************************************************
*/
void Run_IicPoll(void)
{
    if(rIICCON & 0x10)                  //Tx/Rx Interrupt Enable
       IicPoll();
}       
    
/*
*********************************************************
* 函数介绍：本函数是iic POLL的程序。				
* 输入参数：无
* 输出参数：无
* 返回值  ：无
*********************************************************
*/
void IicPoll(void)
{
    U32 iicSt,i;
    
    iicSt = rIICSTAT; 
    if(iicSt & 0x8){}                   //When bus arbitration is failed.
    if(iicSt & 0x4){}                   //When a slave address is matched with IICADD
    if(iicSt & 0x2){}                   //When a slave address is 0000000b
    if(iicSt & 0x1){}                   //When ACK isn't received

    switch(_iicMode)
    {
        case POLLACK:
            _iicStatus = iicSt;
            break;

        case RDDATA:
            if((_iicDataCount--)==0)
            {
                _iicData[_iicPt++] = rIICDS;
            
                rIICSTAT = 0x90;                //Stop MasRx condition 
                rIICCON  = 0xaf;                //Resumes IIC operation.
                Delay(1);                       //Wait until stop condtion is in effect.
                                                //Too long time... 
                                                //The pending bit will not be set after issuing stop condition.
                break;    
            }      
            _iicData[_iicPt++] = rIICDS;
                        //The last data has to be read with no ack.
            if((_iicDataCount)==0)
                rIICCON = 0x2f;                 //Resumes IIC operation with NOACK.  
            else 
                rIICCON = 0xaf;                 //Resumes IIC operation with ACK
            break;

        case WRDATA:
            if((_iicDataCount--)==0)
            {
                rIICSTAT = 0xd0;                //stop MasTx condition 
                rIICCON  = 0xaf;                //resumes IIC operation.
                Delay(1);                       //wait until stop condtion is in effect.
                       //The pending bit will not be set after issuing stop condition.
                break;    
            }
            rIICDS = _iicData[_iicPt++];        //_iicData[0] has dummy.
            for(i=0;i<10;i++);                  //for setup time until rising edge of IICSCL
            rIICCON = 0xaf;                     //resumes IIC operation.
            break;

        case SETRDADDR:
//            Uart_Printf("IicPoll() SETRADDR [S%d]",_iicDataCount);
            if((_iicDataCount--)==0)
            {
                break;                  //IIC operation is stopped because of IICCON[4]    
            }
            rIICDS = _iicData[_iicPt++];
            for(i=0;i<10;i++);          //for setup time until rising edge of IICSCL
            rIICCON = 0xaf;             //resumes IIC operation.
            break;

        default:
            break;      
    }
}