谁能说说44B0的I2C是怎么工作的？

只看该作者 · 2009-2-6 10:02

自己写了一下没有成功，下面是给的例程，用中断的方法来发送一个Byte，红色的部分都好理解，分别写器件地址，子地址，数据，每发送完一个字节产生一次中断，发完了停止总线。
问题是，它上面的每个字节发完之后都不等ACK，直到发完，总线停止了以后，来到蓝色部分，在这里等ACK？？？而且这时还是设rIICSTAT=0xf0;就是主器件发送模式，再发送一次器件地址，然后等ACK，这是从何说起啊？？
另外，44B0是否无法用I/O口来模拟I2C了？要频繁更改I/O口的属性，似乎时间上来不及，不知道为什么ARM的I/O口都要这样设计，不像51的是输入输出的？？

void Wr24C040(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
  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.
}

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

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

    default:
        break;
    }
}