iic.c

这是EEPROM芯片AT24C32的驱动程序

#include <string.h>
#include "..\inc\44b.h"
#include "..\inc\44blib.h"
#include "..\inc\def.h"
#include "..\inc\iic.h"

#define WRDATA	    (1)
#define POLLACK     (2)
#define RDDATA	    (3)
#define SETRDADDR   (4)

#define IICBUFSIZE 0x20

U8 _iicData[IICBUFSIZE];
volatile int _iicDataCount;  //总的数据数 
volatile int _iicStatus;    //当前的状态
volatile int _iicMode;     //在那一种工作模式
int _iicPt;

void __irq IicInt(void);

void Test_Iic(void)
{
    unsigned int i,j,save_F,save_PF;
    static U8 data[256];

    Uart_Printf("[IIC Test using KS24C080]\n");

    save_F=rPCONF;
    save_PF=rPUPF;
    rPCONF |=0xa;	//PF0:IICSCL, PF1:IICSDA
   // rPCONF&=0x3ffffa;
    rPUPF |=0x3;	//pull-up disable

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

    rIICCON=(1<<7)|(0<<6)|(1<<5)|(0xf);
    //Enable interrupt, IICCLK=MCLK/16, Enable ACK
    //40Mhz/16/(15+1) = 257Khz	
    rIICADD=0x10;   // S3C44B0X slave address    为什么是0X10???

    rIICSTAT=0x10;

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

    for(i=0;i<256;i++)
	//Wr24C040(0xa0,(U16)i,33);
    for(i=0;i<256;i++)
	data[i]=0;

    Uart_Printf("Read test data from KS24C080\n");
    for(i=0;i<256;i++)
	Rd24C040(0xa0,(U16)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");
    }
    
    rPCONF=save_F;
    rPUPF=save_PF;
}


void Wr24C040(U32 slvAddr,U32 addr,U8 data)    //Wr24C040(0xa0,(U8)i,i)
{
    _iicMode=WRDATA;// WRDATA=1
    _iicPt=0;
    _iicData[1]=(U8)addr;   
    _iicData[0]=(U8)(addr>>8);
   
    _iicData[2]=data;
    
    _iicDataCount=3;
    
    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;//POLLACK=2

    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.
}

/*void Wr24C040(U32 slvAddr,U32 addr,U8 data)    //Wr24C040(0xa0,(U8)i,i)
{
    _iicMode=WRDATA;// WRDATA=1
    _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;//POLLACK=2

    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.
}*/	

void Rd24C040(U32 slvAddr,U32 addr,U8 *data)   //Rd24C040(0xa0,(U8)i,&(data[i])); 
{
    _iicMode=SETRDADDR;
    _iicPt=0;
    _iicData[0]=(U8)(addr>>8);
    _iicData[1]=(U8)(addr);
    _iicDataCount=2;

    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];
    Uart_Printf("%2x ",_iicData[0]);
    Uart_Printf("%2x ",_iicData[1]);
    
}



void __irq IicInt(void)
{
    U32 iicSt,i;
    rI_ISPC=BIT_IIC;

    iicSt=rIICSTAT; //  读IIC的状态
    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:  //POLLACK=2
	    _iicStatus=iicSt;
	    break;

	case RDDATA:  //RDDATA=3
	    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:   //WRDATA=1
	    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:   //SETRDADDR=4
	    //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;	  
    }
}