请教大师帮俺看看6747的I2C接口调试

只看该作者 · 2013-9-16 09:30

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   你好。I2C接口调试不通过，想请教一下，是怎么回事，我用示波器测试输出的SCL口，硬件的从地址已经输出来了，但是没有数据输出。程序调用出错，C6747_I2C_write（）返回值正常应该是0，怎么老是返回-1。感觉好像就没有将数据发送出去一样，好像是寄存器配置有问题，但仔细看了遍，也没发现是什么问题呀，请你多多帮忙，谢谢！
Int16 C6747_I2C_write( Uint16 i2c_addr, Uint8* data, Uint16 len )
{

      C6747_wait( 10 );                      // Short delay

      for ( i = 0 ; i < len ; i++ )
      {
         I2C_ICDXR = data[i];          // Write

         timeout = i2c_timeout;
         do
         {
            if ( timeout-- < 0  )
            {
                  C6747_I2C_reset( );
                  return -1;
            }
         } while ( ( I2C_ICSTR & ICSTR_ICXRDY ) == 0 );// Wait for Tx Ready
      }

      I2C_ICMDR |= ICMDR_STP;          // Generate STOP

      return 0;

}

俺又仔细看了一遍，在while ( ( I2C_ICSTR & ICSTR_ICXRDY ) == 0 );// Wait for Tx Ready
查看寄存值为I2C_ICSTR =0X1406.IRS位在寄存器ICMDR中已经置位了，根据提示

应该是The I2C has received or transmitted a START bit on the bus.可是需要怎么设置呢，我搞了两天了也没搞出来。

真的是无语了。。。。。。。寄存器设置如下：
      I2C_ICMDR  = 0;                   // Reset I2C
      I2C_ICMDR  = ICMDR_TRX             // set for Transmitter mode
               | ICMDR_MST;             // Set for Master Write

      I2C_ICSAR  = i2c_addr;             // Set I2C slave address
      I2C_ICPSC  = 9;             // Prescale to get 7.5MHz I2C internal
      I2C_ICCLKL = 15;             // Config clk LOW for 100kHz
      I2C_ICCLKH = 40;             // Config clk HIGH for 100kHz
   I2C_ICSTR  = I2C_ICSTR;
  while (!(I2C_ICIVR == 0));

      I2C_ICMDR |= ICMDR_IRS;       // Release I2C from reset

  while (!(( I2C_ICSTR & ICSTR_BB ) == 0 ));
      I2C_ICMDR |= ICMDR_STT;
      //以上都是按TI手册中Configuring the I2C 步骤来的，已经核对了，没有发现问题