iic.c

一个关于制作IC卡的源代码

/*
*********************************************************
* Copyright (c)
* All rights reserved.				            
*
* 文件名称：iic.c
* 文件标识：
* 摘    要：本文件是对iic进行初始化和操作。
* 当前版本：1.0
* 作    者：冯富秋
* 完成日期：2006.4.3
*
* 取代版本：
* 作    者：
* 完成日期：
*********************************************************
*/

/*
*********************************************************
*   					 头文件
*********************************************************
*/

#include <string.h>
#include "2440addr.h"
#include "2440lib.h"
#include "def.h"
#include "IIC.h"

static volatile U8 _iicData[IICBUFSIZE];
static volatile int _iicDataCount;
static volatile int _iicStatus;
static volatile int _iicMode;
static volatile int save_E,save_PE;
static int _iicPt;
 
//*************************[ 中断方式的初始化函数 ]**************************** 
void IIC_Init_IRQ(void)
{
	save_E   = rGPECON;
    save_PE  = rGPEUP;
    rGPEUP  |= 0xc000;                  //Pull-up disable
    rGPECON |= 0xa00000;                //GPE15:IICSDA , GPE14:IICSCL 

    pISR_IIC = (unsigned)IicInt;
    rINTMSK &= ~(BIT_IIC);

      //Enable ACK, Prescaler IICCLK=PCLK/16, Enable interrupt, Transmit clock value Tx clock=IICCLK/16
      // If PCLK 50.7MHz, IICCLK = 3.17MHz, Tx Clock = 0.198MHz
    rIICCON = (1<<7) | (0<<6) | (1<<5) | (0xf);

    rIICADD  = 0x10;                    //2440 slave address = [7:1]
    rIICSTAT = 0x10;                    //IIC bus data output enable(Rx/Tx)
	rIICLC = (1<<2)|(1);  				// Filter enable, 15 clocks SDA output delay       added by junon
}

//*************************[ 轮询方式的初始化函数 ]**************************** 
void IIC_Init(void)
{
	save_E   = rGPECON;
    save_PE  = rGPEUP;
    rGPEUP  |= 0xc000;                  //Pull-up disable
    rGPECON |= 0xa00000;                //GPE15:IICSDA , GPE14:IICSCL 

    pISR_IIC = (unsigned)IicInt;
    rINTMSK |= BIT_IIC;

      //Enable ACK, Prescaler IICCLK=PCLK/16, Enable interrupt, Transmit clock value Tx clock=IICCLK/16
      // If PCLK 50.7MHz, IICCLK = 3.17MHz, Tx Clock = 0.198MHz
    rIICCON = (1<<7) | (0<<6) | (1<<5) | (0xf);

    rIICADD  = 0x10;                    //2440 slave address = [7:1]
    rIICSTAT = 0x10;                    //IIC bus data output enable(Rx/Tx)
	rIICLC = (1<<2)|(1);  				// Filter enable, 15 clocks SDA output delay       added by junon	
}
//*************************[ 恢复函数 ]**************************** 
void IIC_Restore(void)
{
	rINTMSK |= BIT_IIC;    
    rGPEUP  = save_PE;
    rGPECON = save_E;
}


//*************************[ 采用中断方式的写函数 ]****************************
void WrIIC(U32 slvAddr,U32 addr,U8 data)
{
    _iicMode      = WRDATA;
    _iicPt        = 0;
    _iicData[0]   = (U8)addr;
    _iicData[1]   = data;
    _iicDataCount = 2;
    
    rIICDS   = slvAddr;                 //0xa0
    rIICSTAT = 0xf0;                    //MasTx,Start
      //Clearing the pending bit isn't needed because the pending bit has been cleared.
    
    while(_iicDataCount!=-1);

    _iicMode = POLLACK;

    while(1)
    {
        rIICDS     = slvAddr;
        _iicStatus = 0x100;
        rIICSTAT   = 0xf0;              //MasTx,Start
        rIICCON    = 0xaf;              //Resumes IIC operation. 
 
        while(_iicStatus==0x100);
           
        if(!(_iicStatus&0x1))
        {
            break;                      //When ACK is received
        }
    }
    rIICSTAT = 0xd0;                    //Stop MasTx condition 
    rIICCON  = 0xaf;                    //Resumes IIC operation. 
    Delay(1);                           //Wait until stop condtion is in effect.
       //Write is completed.
}
        
//**********************[ 采用中断方式的读函数 ] ***********************************
void RdIIC(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);

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

    *data = _iicData[1];
}


//**********************[ 用中断方式的中断例程 ] ***********************************
void __irq IicInt(void)
{
    U32 iicSt,i;
    
    rSRCPND = BIT_IIC;          //Clear pending bit
    rINTPND = BIT_IIC;
    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("[ 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;      
    }
}

//**************[ 采用轮询方式的写函数 ]*****************************************
void _WrIIC(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(30);                           //Wait until stop condtion is in effect.
      //Write is completed.
}
        
//************************[ 采用轮询方式的读函数 ]********************************
void _RdIIC(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];
}

//**********************[ 轮询函数 ]*********************************
void Run_IicPoll(void)
{
    if(rIICCON & 0x10)                  //Tx/Rx Interrupt Enable
       IicPoll();
}       
    
//**********************[ 轮询处理函数 ]**************************************
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("[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;      
    }
}