TM4C123的I2C失去总线控制？？

不知有谁在I2C上研究得比较深 我读MPU9250设备ID 有时能读到有时候不能 我在读写函数的结尾加了条while(!(I2CMasterErr(I2C3_BASE)==I2C_MASTER_ERR_NONE)); 程序就卡这里了 我改成ERR_ARB_LOST就通过了 翻译过来是失去总线控制 出现这种错误会是什么原因啊

下面是我的读写函数 请各路高手检查下有没有错误

void MPU_Write_Byte(uint8_t addr,uint8_t reg,uint8_t data)
{
 I2CMasterSlaveAddrSet(I2C3_BASE,addr,false);
 I2CMasterDataPut(I2C3_BASE,reg);
 I2CMasterControl(I2C3_BASE,I2C_MASTER_CMD_BURST_SEND_START);
 while(I2CMasterBusy(I2C3_BASE));
 I2CMasterDataPut(I2C3_BASE,data);
 I2CMasterControl(I2C3_BASE,I2C_MASTER_CMD_BURST_SEND_CONT);
 while(I2CMasterBusy(I2C3_BASE));
 while(!(I2CMasterErr(I2C3_BASE)==I2C_MASTER_ERR_NONE));
 I2CMasterControl(I2C3_BASE,I2C_MASTER_CMD_BURST_SEND_FINISH);
}

uint8_t MPU_Read_Byte(uint8_t addr,uint8_t reg)
{
 uint8_t res;
 I2CMasterSlaveAddrSet(I2C3_BASE,addr,false);
  I2CMasterDataPut(I2C3_BASE,reg);
 I2CMasterControl(I2C3_BASE,I2C_MASTER_CMD_BURST_SEND_START);
 while(I2CMasterBusy(I2C3_BASE));
 I2CMasterSlaveAddrSet(I2C3_BASE,addr,true);
  I2CMasterControl(I2C3_BASE,I2C_MASTER_CMD_SINGLE_RECEIVE);
  while(I2CMasterBusy(I2C3_BASE));
 while(!(I2CMasterErr(I2C3_BASE)==I2C_MASTER_ERR_NONE));
  res=I2CMasterDataGet(I2C3_BASE);
  return res;
}

void MPU_Read_Len(uint8_t addr,uint8_t reg,uint8_t len,uint8_t *buf)
{
 uint32_t DataNumber;
 uint32_t MsterCMD;
 I2CMasterSlaveAddrSet(I2C3_BASE,addr,false);
 I2CMasterDataPut(I2C3_BASE,reg);
 I2CMasterControl(I2C3_BASE,I2C_MASTER_CMD_SINGLE_SEND);
  while(I2CMasterBusy(I2C3_BASE));
  I2CMasterSlaveAddrSet(I2C3_BASE,addr,true);
 
 for(DataNumber=0;DataNumber<len;DataNumber++)
 {
  if(DataNumber==0)
  {
   MsterCMD=I2C_MASTER_CMD_BURST_RECEIVE_START;
  }
  else if(DataNumber==(len-1))
  {
   MsterCMD=I2C_MASTER_CMD_FIFO_BURST_RECEIVE_FINISH;
  }
  else
  {
   MsterCMD=I2C_MASTER_CMD_BURST_RECEIVE_CONT;
  }
  I2CMasterControl(I2C3_BASE,MsterCMD);
   while(I2CMasterBusy(I2C3_BASE));
  while(!(I2CMasterErr(I2C3_BASE)==I2C_MASTER_ERR_NONE));
  *buf=I2CMasterDataGet(I2C3_BASE);
  buf++;
 }

}