iic.c

S3C2410学习的基础资料 大部分实验源码及工程

//====================================================================
// File Name : 2410IIC.c
// Function  : S3C2410 IIC-bus Master Tx/Rx mode Test Program
//             (Interrupt / Non Interrupt (Polling))
// Program   : Shin, On Pil (SOP)
// Date      : May 21, 2002
// Version   : 0.0
// History
//   0.0 : Programming start (March 11, 2002) -> SOP
//====================================================================

#include "def.h"
#include "2410addr.h"
#include "2410lib.h"
#include "IIC.h"

static U8 iicData[IICBUFSIZE];
static volatile int iicDataCount;
static volatile int iicStatus;
static volatile int iicMode;
static int iicPt;


/*********************************************************
       SMDK2410 IIC configuration
  GPE15=IICSDA, GPE14=IICSCL
  "Non-Interrupt" mode for IIC block
 *********************************************************/
void Test_IIC(void)
{
    unsigned int i,j;
    static U8 data[256];
    Uart_Printf("IIC Test(Polling) using AT24C02\n");

    //设置GPE15->IICSDA和GPE14->IICSCL
    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");
	
	//写入一个page的数据，page的大小是256byte，
    //page 的起始地址是0xa0，写入的数据是：0、1、2、...255。0xa0是AT24C02的页地址。
    //AT24C02的页地址是0x00/0x20/0x40/0x60/0x80/0xa0/0xc0/0xe0。
    for(i=0;i<256;i++)
       Wr24C02(0xa0,(U8)i,i);//U32 slvAddr,U32 addr,U8 data
    
    //初始化data数组的值为0。
    for(i=0;i<256;i++)
        data[i] = 0;
    Uart_Printf("Read test data from AT24C02\n");
    
    //读24C02的0xa0地址中数据到data数组中。
    for(i=0;i<256;i++)
        Rd24C02(0xa1,(U8)i,&(data[i])); 
    //输出data数组接收数据的值
    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");
}

//**************[ _Wr24C080 ]*****************************************
void Wr24C02(U32 slvAddr,U32 addr,U8 data)
{
    iicMode      = WRDATA;
    iicPt        = 0;
    iicData[0]   = (U8)addr;
    iicData[1]   = data;
    iicDataCount = 2;
    
    //8-bit data shift register for IIC-bus Tx/Rx operation.
    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.
}
        
//************************[ _Rd24C080 ]********************************
void Rd24C02(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  = 0xe0;//0xaf;                    //Resumes IIC operation.	//hzh
    while(iicDataCount!=-1)
        Run_IicPoll();

    *data = iicData[1];
}

//**********************[ Run_IicPoll ]*********************************
void Run_IicPoll(void)
{
    if(rIICCON & 0x10)                  //Tx/Rx Interrupt Enable
       IicPoll();
}       
    
//**********************[IicPoll ]**************************************
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  = 0xe0;//0xaf;                //Resumes IIC operation.	//hzh
                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 = 0x60;//0x2f;                 //Resumes IIC operation with NOACK.  	//hzh
            else 
                rIICCON = 0xe0;//0xaf;                 //Resumes IIC operation with ACK	//hzh
            break;

        case WRDATA:
            if((iicDataCount--)==0)
            {
                rIICSTAT = 0xd0;                //stop MasTx condition 
                rIICCON  = 0xe0;//0xaf;                //resumes IIC operation.	//hzh
                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 = 0xe0;//0xaf;                     //resumes IIC operation.	//hzh
            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 = 0xe0;//0xaf;             //resumes IIC operation.	//hzh
            break;

        default:
            break;      
    }
}