S3C2440 IIC总线接口

时间：11-21 来源：互联网点击：

#include
#include"2440addr.h"
#include"2440lib.h"
#include"def.h"
#defineWRDATA(1)
#definePOLLACK(2)
#defineRDDATA(3)
#defineSETRDADDR(4)
#defineIICBUFSIZE0x20
staticU8iicData[IICBUFSIZE];
staticvolatileintiicDataCount;
staticvolatileintiicStatus;
staticvolatileintiicMode;
staticintiicPt;
voidWr24C02(U32slvAddr,U32addr,U8data);
voidRd24C02(U32slvAddr,U32addr,U8*data);
voidIicPoll(void);
voidRun_IicPoll(void);
voidMain(void)
{
unsignedinti,j;
staticU8data[256];//用于存储AT24C02读出的数据
SelectFclk(2);//设置系统时钟400M
ChangeClockDivider(2,1);//设置分频1：4：8
CalcBusClk();//计算总线频率
rGPHCON&=~((3<4)|(3<6));
rGPHCON|=(2<4)|(2<6);//GPH2--TXD[0];GPH3--RXD[0]
rGPHUP=0x00;//使能上拉功能
Uart_Init(0,115200);
Uart_Select(0);
Uart_Printf("[IICTest(Polling)usingAT24C020]\n");
rGPEUP|=0xc000;//关上拉
rGPECON&=~0xf0000000;
rGPECON|=0xa0000000;//GPE15:IICSDA,GPE14:IICSCL
//使能应答,IIC总线时钟IICCLK=PCLK/16,使能中断,发送时钟IICCLK/16
rIICCON=(1<7)|(0<6)|(1<5)|(0xf);
rIICADD=0x10;//2440从机地址=[7:1]
rIICSTAT=0x10;//IIC总线数据输出使能(Rx/Tx)
Uart_Printf("WritetestdataintoAT24C02\n");
for(i=0;i<256;i++)
Wr24C02(0xa0,(U8)i,i);//写入数据到AT24C02
for(i=0;i<256;i++)//数组数据清零
data[i]=0;
Uart_Printf("ReadtestdatafromAT24C02\n");
for(i=0;i<256;i++)
Rd24C02(0xa0,(U8)i,&(data[i]));//读取AT24C02的数据放入data数组中
for(i=0;i<16;i++)
{
for(j=0;j<16;j++)
Uart_Printf("%2x",data[i*16+j]);//打印从AT24C02读出的数据
Uart_Printf("\n");
}
}
voidWr24C02(U32slvAddr,U32addr,U8data)//slvAddr为从地址
{//addr为字节地址，data为写入的数据
iicMode=WRDATA;//写数据模式
iicPt=0;
iicData[0]=(U8)addr;
iicData[1]=data;
iicDataCount=2;//根据AT24C02字节写的发式，要写从地址和字节地址
rIICDS=slvAddr;//把0xa0地址写入到数据移位寄存器IICDS
//MasterTxmode,Start(Write),IIC-busdataoutputenable
//Busarbitrationsucessful,AddressasslavestatusflagCleared,
//Addresszerostatusflagcleared,Lastreceivedbitis0
rIICSTAT=0xf0;//
//Clearingthependingbitisntneededbecausethependingbithasbeencleared.
while(iicDataCount!=-1)
Run_IicPoll();
iicMode=POLLACK;
while(1)
{
rIICDS=slvAddr;
iicStatus=0x100;//Tocheckif_iicStatusischanged
rIICSTAT=0xf0;//MasterTx,Start,OutputEnable,Sucessful,Cleared,Cleared,0
rIICCON=0xaf;//ResumesIICoperation.
while(iicStatus==0x100)
Run_IicPoll();
if(!(iicStatus&0x1))
break;//WhenACKisreceived
}
rIICSTAT=0xd0;//MasterTxcondition,Stop(Write),OutputEnable
rIICCON=0xaf;//ResumesIICoperation.
Delay(1);//Waituntilstopcondtionisineffect.
//Writeiscompleted.
}
//************************[_Rd24C02]********************************
voidRd24C02(U32slvAddr,U32addr,U8*data)
{
iicMode=SETRDADDR;//设置要从从机读取数据的从地址
iicPt=0;
iicData[0]=(U8)addr;
iicDataCount=1;//写从地址
rIICDS=slvAddr;
rIICSTAT=0xf0;//MasTx,Start
//Clearingthependingbitisntneededbecausethependingbithasbeencleared.
while(iicDataCount!=-1)
Run_IicPoll();
iicMode=RDDATA;//读数据模式
iicPt=0;
iicDataCount=1;//
rIICDS=slvAddr;
rIICSTAT=0xb0;//MasterRx,Start
rIICCON=0xaf;//ResumesIICoperation.
while(iicDataCount!=-1)
Run_IicPoll();
*data=iicData[1];
}
voidRun_IicPoll(void)
{
if(rIICCON&0x10)//Tx/Rx中断使能
IicPoll();
}
voidIicPoll(void)
{
U32iicSt,i;
iicSt=rIICSTAT;//ICC状态寄存器
if(iicSt&0x8){}//总线仲裁失败
if(iicSt&0x4){}//从地址与ICCADD地址匹配
if(iicSt&0x2){}//从地址为00000000b
if(iicSt&0x1){}//未收到ACK
switch(iicMode)
{
casePOLLACK:
iicStatus=iicSt;
break;
caseRDDATA://从从机中读取数据
if((iicDataCount--)==0)
{
iicData[iicPt++]=rIICDS;
rIICSTAT=0x90;//StopMasRxcondition
rIICCON=0xaf;//ResumesIICoperation.
Delay(1);//Waituntilstopcondtionisineffect.
//Toolongtime...
//Thependingbitwillnotbesetafterissuingstopcondition.
break;
}
iicData[iicPt++]=rIICDS;
//Thelastdatahastobereadwithnoack.
if((iicDataCount)==0)
rIICCON=0x2f;//ResumesIICoperationwithNOACK.
else
rIICCON=0xaf;//ResumesIICoperationwithACK
break;
caseWRDATA://写数据到从机
if((iicDataCount--)==0)
{
rIICSTAT=0xd0;//st

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