C2000中 ADC采样计算电流电压的问题

有关电流电压的计算过程，很不理解，根据读取到的DAC值计算实际值的时候，电流计算为什么不需要除以4096乘以3.3，再减去偏置，再除以放大倍数和测量电阻的乘积？

以下程序求具体解释：

static inline void HAL_readAdcData(HAL_Handle handle,HAL_AdcData_t *pAdcData)
{
  HAL_Obj *obj = (HAL_Obj *)handle;

  _iq value;
  _iq current_sf = HAL_getCurrentScaleFactor(handle);
  _iq voltage_sf = HAL_getVoltageScaleFactor(handle);


  // convert current A
  // sample the first sample twice due to errata sprz342f, ignore the first sample
  value = (_iq)ADC_readResult(obj->adcHandle,ADC_ResultNumber_1);
  value = _IQ12mpy(value,current_sf) - obj->adcBias.I.value[0];      // divide by 2^numAdcBits = 2^12
  pAdcData->I.value[0] = value;

  // convert current B
  value = (_iq)ADC_readResult(obj->adcHandle,ADC_ResultNumber_2);
  value = _IQ12mpy(value,current_sf) - obj->adcBias.I.value[1];      // divide by 2^numAdcBits = 2^12
  pAdcData->I.value[1] = value;

  // convert current C
  value = (_iq)ADC_readResult(obj->adcHandle,ADC_ResultNumber_3);
  value = _IQ12mpy(value,current_sf) - obj->adcBias.I.value[2];      // divide by 2^numAdcBits = 2^12
  pAdcData->I.value[2] = value;

  // convert voltage A
  value = (_iq)ADC_readResult(obj->adcHandle,ADC_ResultNumber_4);
  value = _IQ12mpy(value,voltage_sf) - obj->adcBias.V.value[0];      // divide by 2^numAdcBits = 2^12
  pAdcData->V.value[0] = value;

  // convert voltage B
  value = (_iq)ADC_readResult(obj->adcHandle,ADC_ResultNumber_5);
  value = _IQ12mpy(value,voltage_sf) - obj->adcBias.V.value[1];      // divide by 2^numAdcBits = 2^12
  pAdcData->V.value[1] = value;

  // convert voltage C
  value = (_iq)ADC_readResult(obj->adcHandle,ADC_ResultNumber_6);
  value = _IQ12mpy(value,voltage_sf) - obj->adcBias.V.value[2];      // divide by 2^numAdcBits = 2^12
  pAdcData->V.value[2] = value;

  // read the dcBus voltage value
  value = (_iq)ADC_readResult(obj->adcHandle,ADC_ResultNumber_7);     // divide by 2^numAdcBits = 2^12
  value = _IQ12mpy(value,voltage_sf);
  pAdcData->dcBus = value;

  return;
} // end of HAL_readAdcData() function