I2C通信问题

只看该作者 · 2013-8-21 09:58

请教各位老师，DSP5505 I2C 与DAC通信，DSP为主设备向DAC发送数据，之前是能工作的，但自从把原来的DAC用热风枪吹下来换了一片DAC，程序运行一直卡在等待发送寄存器准备状态（红色标出），单步运行可以通过，请问有遇到此类问题的老师吗，是DSP的问题还是DAC的问题，难道是DSP虚焊了？请各位老师不吝赐教，小弟感激不尽~~~~

Int16 I2C_DAC_write(int chan_num, Uint16 data)
{
      Int16  timeout, i;
      Uint8  control_byte,data1,data2;
      Uint8  i2cdata[3] = {0,0,0};
      Uint16 len  = 3;                // number of data word to be transmitted
      Uint8  i2c_addr = 0x4F;                //DAC slave address
//I2C_IER = 0x0000;
      I2C_CNT = len;                   // Set number of bytes(data word) to write
      I2C_SAR = i2c_addr;             // Set I2C slave address
      I2C_MDR |= MDR_STT                // start
               | MDR_TRX             // transmit
               | MDR_MST             // master
               | MDR_IRS             // Release from reset
               | MDR_FREE;          // free run regardless of the breakpoint

      wait(5);                      // Short delay


/**************control byte to be transmitted**********************************************/
      switch(chan_num)
{
case 0: control_byte = 0x10;
break;
case 1: control_byte = 0x12;
break;
case 2: control_byte = 0x14;
break;
case 3: control_byte = 0x16;
break;
default:
while(1);
}

/* *********change the 16bit word to 8 bit byte,MSB first to be transmitted **************/
      data1  = (data & 0x0FF0);
      data1  = data1 >> 4;
      data2 = (data & 0x000F);
      data2 = data2 << 4;

      i2cdata[0] = control_byte;  //control byte
      i2cdata[1] = (Uint8)data1; //MSB data
      i2cdata[2] = (Uint8)data2; //LSB data




/***********发送数据***********************************************/
      for ( i = 0 ; i < len ; i++ )
      {
         I2C_DXR = i2cdata;          // Write
         while ( ( I2C_STR & STR_XRDY ) == 0 ); //wait for TX ready

      }


      I2C_MDR |= MDR_STP;          // Generate STOP

wait(100);

      return 0;

}