tmpccer &= (uint16_t)~((uint16_t)TIM_CCER_CC3P);
  tmpccer |= (uint16_t)(TIM_OCPolarity << 8);
  /* Write to TIMx CCER register */
  TIMx->CCER = tmpccer;
}

/**
  * @brief  Configures the TIMx channel 4 polarity.
  * @param  TIMx: where x can be 2, 3 or 4 to select the TIM peripheral.
  * @param  TIM_OCPolarity: specifies the OC4 Polarity
  *   This parmeter can be one of the following values:
  *     @arg TIM_OCPolarity_High: Output Compare active high
  *     @arg TIM_OCPolarity_Low: Output Compare active low
  * @retval None
  */
void TIM_OC4PolarityConfig(TIM_TypeDef* TIMx, uint16_t TIM_OCPolarity)
{
  uint16_t tmpccer = 0;
  
  /* Check the parameters */
  assert_param(IS_TIM_LIST3_PERIPH(TIMx));
  assert_param(IS_TIM_OC_POLARITY(TIM_OCPolarity));
  
  tmpccer = TIMx->CCER;
  /* Set or Reset the CC4P Bit */
  tmpccer &= (uint16_t)~((uint16_t)TIM_CCER_CC4P);
  tmpccer |= (uint16_t)(TIM_OCPolarity << 12);
  /* Write to TIMx CCER register */
  TIMx->CCER = tmpccer;
}

/**
  * @brief  Selects the OCReference Clear source.
  * @param  TIMx: where x can be 2, 3 or 4 to select the TIM peripheral.
  * @param  TIM_OCReferenceClear: specifies the OCReference Clear source.
  *   This parameter can be one of the following values:
  *     @arg TIM_OCReferenceClear_ETRF: The internal OCreference clear input is connected to ETRF.
  *     @arg TIM_OCReferenceClear_OCREFCLR: The internal OCreference clear input is connected to OCREF_CLR input.  
  * @retval None
  */
void TIM_SelectOCREFClear(TIM_TypeDef* TIMx, uint16_t TIM_OCReferenceClear)
{
  /* Check the parameters */
  assert_param(IS_TIM_LIST3_PERIPH(TIMx));
  assert_param(TIM_OCREFERENCECECLEAR_SOURCE(TIM_OCReferenceClear));

  /* Set the TIM_OCReferenceClear source */
  TIMx->SMCR &=  (uint16_t)~((uint16_t)TIM_SMCR_OCCS);
  TIMx->SMCR |=  TIM_OCReferenceClear;
}

/**
  * @brief  Enables or disables the TIM Capture Compare Channel x.
  * @param  TIMx: where x can be 2, 3, 4, 9, 10 or 11 to select the TIM peripheral.
  * @param  TIM_Channel: specifies the TIM Channel
  *   This parameter can be one of the following values:
  *     @arg TIM_Channel_1: TIM Channel 1
  *     @arg TIM_Channel_2: TIM Channel 2
  *     @arg TIM_Channel_3: TIM Channel 3
  *     @arg TIM_Channel_4: TIM Channel 4
  * @param  TIM_CCx: specifies the TIM Channel CCxE bit new state.
  *   This parameter can be: TIM_CCx_Enable or TIM_CCx_Disable. 
  * @retval None
  */
void TIM_CCxCmd(TIM_TypeDef* TIMx, uint16_t TIM_Channel, uint16_t TIM_CCx)
{
  uint16_t tmp = 0;

  /* Check the parameters */
  assert_param(IS_TIM_LIST1_PERIPH(TIMx)); 
  assert_param(IS_TIM_CCX(TIM_CCx));

  tmp = CCER_CCE_SET << TIM_Channel;

  /* Reset the CCxE Bit */
  TIMx->CCER &= (uint16_t)~ tmp;

  /* Set or reset the CCxE Bit */ 
  TIMx->CCER |=  (uint16_t)(TIM_CCx << TIM_Channel);
}

/**
  * @}
  */

/** @defgroup TIM_Group3 Input Capture management functions
 *  @brief    Input Capture management functions 
 *
@verbatim   
 ===============================================================================
                      Input Capture management functions
 ===============================================================================  
   
       ===================================================================      
              TIM Driver: how to use it in Input Capture Mode
       =================================================================== 
       To use the Timer in Input Capture mode, the following steps are mandatory:
       
       1. Enable TIM clock using RCC_APBxPeriphClockCmd(RCC_APBxPeriph_TIMx, ENABLE) function
       
       2. Configure the TIM pins by configuring the corresponding GPIO pins
       
       2. Configure the Time base unit as described in the first part of this driver, if needed,
          else the Timer will run with the default configuration:
          - Autoreload value = 0xFFFF
          - Prescaler value = 0x0000
          - Counter mode = Up counting
          - Clock Division = TIM_CKD_DIV1
          
       3. Fill the TIM_ICInitStruct with the desired parameters including:
          - TIM Channel: TIM_Channel
          - TIM Input Capture polarity: TIM_ICPolarity
          - TIM Input Capture selection: TIM_ICSelection
          - TIM Input Capture Prescaler: TIM_ICPrescaler
          - TIM Input CApture filter value: TIM_ICFilter
       
       4. Call TIM_ICInit(TIMx, &TIM_ICInitStruct) to configure the desired channel with the 
          corresponding configuration and to measure only frequency or duty cycle of the input signal,
          or,
          Call TIM_PWMIConfig(TIMx, &TIM_ICInitStruct) to configure the desired channels with the 
          corresponding configuration and to measure the frequency and the duty cycle of the input signal
          
       5. Enable the NVIC or the DMA to read the measured frequency. 
          
       6. Enable the corresponding interrupt (or DMA request) to read the Captured value,
          using the function TIM_ITConfig(TIMx, TIM_IT_CCx) (or TIM_DMA_Cmd(TIMx, TIM_DMA_CCx)) 
       
       7. Call the TIM_Cmd(ENABLE) function to enable the TIM counter.
       
       8. Use TIM_GetCapturex(TIMx); to read the captured value.
       
       Note1: All other functions can be used seperatly to modify, if needed,
          a specific feature of the Timer. 

@endverbatim
  * @{
  */

/**
  * @brief  Initializes the TIM peripheral according to the specified
  *         parameters in the TIM_ICInitStruct.
  * @param  TIMx: where x can be 2, 3, 4, 9, 10 or 11 to select the TIM peripheral.
  * @param  TIM_ICInitStruct: pointer to a TIM_ICInitTypeDef structure
  *         that contains the configuration information for the specified TIM 
  *         peripheral.
  * @retval None
  */
void TIM_ICInit(TIM_TypeDef* TIMx, TIM_ICInitTypeDef* TIM_ICInitStruct)
{
  /* Check the parameters */
  assert_param(IS_TIM_LIST1_PERIPH(TIMx));
  assert_param(IS_TIM_IC_POLARITY(TIM_ICInitStruct->TIM_ICPolarity));
  assert_param(IS_TIM_IC_SELECTION(TIM_ICInitStruct->TIM_ICSelection));
  assert_param(IS_TIM_IC_PRESCALER(TIM_ICInitStruct->TIM_ICPrescaler));
  assert_param(IS_TIM_IC_FILTER(TIM_ICInitStruct->TIM_ICFilter));
  
  if (TIM_ICInitStruct->TIM_Channel == TIM_Channel_1)
  {
    /* TI1 Configuration */
    TI1_Config(TIMx, TIM_ICInitStruct->TIM_ICPolarity,
               TIM_ICInitStruct->TIM_ICSelection,
               TIM_ICInitStruct->TIM_ICFilter);
    /* Set the Input Capture Prescaler value */
    TIM_SetIC1Prescaler(TIMx, TIM_ICInitStruct->TIM_ICPrescaler);
  }
  else if (TIM_ICInitStruct->TIM_Channel == TIM_Channel_2)
  {
    /* TI2 Configuration */
    TI2_Config(TIMx, TIM_ICInitStruct->TIM_ICPolarity,
               TIM_ICInitStruct->TIM_ICSelection,
               TIM_ICInitStruct->TIM_ICFilter);
    /* Set the Input Capture Prescaler value */
    TIM_SetIC2Prescaler(TIMx, TIM_ICInitStruct->TIM_ICPrescaler);
  }
  else if (TIM_ICInitStruct->TIM_Channel == TIM_Channel_3)
  {
    /* TI3 Configuration */
    TI3_Config(TIMx,  TIM_ICInitStruct->TIM_ICPolarity,
               TIM_ICInitStruct->TIM_ICSelection,
               TIM_ICInitStruct->TIM_ICFilter);
    /* Set the Input Capture Prescaler value */
    TIM_SetIC3Prescaler(TIMx, TIM_ICInitStruct->TIM_ICPrescaler);
  }
  else
  {
    /* TI4 Configuration */
    TI4_Config(TIMx, TIM_ICInitStruct->TIM_ICPolarity,
               TIM_ICInitStruct->TIM_ICSelection,
               TIM_ICInitStruct->TIM_ICFilter);
    /* Set the Input Capture Prescaler value */
    TIM_SetIC4Prescaler(TIMx, TIM_ICInitStruct->TIM_ICPrescaler);
  }
}

/**
  * @brief  Fills each TIM_ICInitStruct member with its default value.
  * @param  TIM_ICInitStruct : pointer to a TIM_ICInitTypeDef structure which will
  *         be initialized.
  * @retval None
  */
void TIM_ICStructInit(TIM_ICInitTypeDef* TIM_ICInitStruct)
{
  /* Set the default configuration */
  TIM_ICInitStruct->TIM_Channel = TIM_Channel_1;
  TIM_ICInitStruct->TIM_ICPolarity = TIM_ICPolarity_Rising;
  TIM_ICInitStruct->TIM_ICSelection = TIM_ICSelection_DirectTI;
  TIM_ICInitStruct->TIM_ICPrescaler = TIM_ICPSC_DIV1;
  TIM_ICInitStruct->TIM_ICFilter = 0x00;
}

/**
  * @brief  Configures the TIM peripheral according to the specified
  *         parameters in the TIM_ICInitStruct to measure an external PWM signal.
  * @param  TIMx: where x can be 2, 3, 4 or 9 to select the TIM peripheral.
  * @param  TIM_ICInitStruct: pointer to a TIM_ICInitTypeDef structure
  *         that contains the configuration information for the specified TIM 
  *         peripheral.
  * @retval None
  */
void TIM_PWMIConfig(TIM_TypeDef* TIMx, TIM_ICInitTypeDef* TIM_ICInitStruct)
{
  uint16_t icoppositepolarity = TIM_ICPolarity_Rising;
  uint16_t icoppositeselection = TIM_ICSelection_DirectTI;
  /* Check the parameters */
  assert_param(IS_TIM_LIST2_PERIPH(TIMx));
  /* Select the Opposite Input Polarity */
  if (TIM_ICInitStruct->TIM_ICPolarity == TIM_ICPolarity_Rising)
  {
    icoppositepolarity = TIM_ICPolarity_Falling;
  }
  else
  {
    icoppositepolarity = TIM_ICPolarity_Rising;
  }
  /* Select the Opposite Input */
  if (TIM_ICInitStruct->TIM_ICSelection == TIM_ICSelection_DirectTI)
  {
    icoppositeselection = TIM_ICSelection_IndirectTI;
  }
  else
  {
    icoppositeselection = TIM_ICSelection_DirectTI;
  }
  if (TIM_ICInitStruct->TIM_Channel == TIM_Channel_1)
  {
    /* TI1 Configuration */
    TI1_Config(TIMx, TIM_ICInitStruct->TIM_ICPolarity, TIM_ICInitStruct->TIM_ICSelection,
               TIM_ICInitStruct->TIM_ICFilter);
    /* Set the Input Capture Prescaler value */
    TIM_SetIC1Prescaler(TIMx, TIM_ICInitStruct->TIM_ICPrescaler);
    /* TI2 Configuration */
    TI2_Config(TIMx, icoppositepolarity, icoppositeselection, TIM_ICInitStruct->TIM_ICFilter);
    /* Set the Input Capture Prescaler value */
    TIM_SetIC2Prescaler(TIMx, TIM_ICInitStruct->TIM_ICPrescaler);
  }
  else
  { 
    /* TI2 Configuration */
    TI2_Config(TIMx, TIM_ICInitStruct->TIM_ICPolarity, TIM_ICInitStruct->TIM_ICSelection,
               TIM_ICInitStruct->TIM_ICFilter);
    /* Set the Input Capture Prescaler value */
    TIM_SetIC2Prescaler(TIMx, TIM_ICInitStruct->TIM_ICPrescaler);
    /* TI1 Configuration */
    TI1_Config(TIMx, icoppositepolarity, icoppositeselection, TIM_ICInitStruct->TIM_ICFilter);
    /* Set the Input Capture Prescaler value */
    TIM_SetIC1Prescaler(TIMx, TIM_ICInitStruct->TIM_ICPrescaler);
  }
}

/**
  * @brief  Gets the TIMx Input Capture 1 value.
  * @param  TIMx: where x can be 2, 3, 4, 9, 10 or 11 to select the TIM peripheral.
  * @retval Capture Compare 1 Register value.

  */
uint32_t TIM_GetCapture1(TIM_TypeDef* TIMx)
{
  /* Check the parameters */
  assert_param(IS_TIM_LIST1_PERIPH(TIMx));
  
  /* Get the Capture 1 Register value */
  return TIMx->CCR1;
}

/**
  * @brief  Gets the TIMx Input Capture 2 value.
  * @param  TIMx: where x can be 2, 3, 4 or 9 to select the TIM peripheral.
  * @retval Capture Compare 2 Register value.

  */
uint32_t TIM_GetCapture2(TIM_TypeDef* TIMx)
{
  /* Check the parameters */
  assert_param(IS_TIM_LIST2_PERIPH(TIMx));
  
  /* Get the Capture 2 Register value */
  return TIMx->CCR2;
}

/**
  * @brief  Gets the TIMx Input Capture 3 value.
  * @param  TIMx: where x can be 2, 3 or 4 to select the TIM peripheral.
  * @retval Capture Compare 3 Register value.
  */
uint32_t TIM_GetCapture3(TIM_TypeDef* TIMx)
{
  /* Check the parameters */
  assert_param(IS_TIM_LIST3_PERIPH(TIMx)); 
  
  /* Get the Capture 3 Register value */
  return TIMx->CCR3;
}

/**
  * @brief  Gets the TIMx Input Capture 4 value.
  * @param  TIMx: where x can be 2, 3 or 4 to select the TIM peripheral.
  * @retval Capture Compare 4 Register value.
  */
uint32_t TIM_GetCapture4(TIM_TypeDef* TIMx)
{
  /* Check the parameters */
  assert_param(IS_TIM_LIST3_PERIPH(TIMx));
  
  /* Get the Capture 4 Register value */
  return TIMx->CCR4;
}

/**
  * @brief  Sets the TIMx Input Capture 1 prescaler.
  * @param  TIMx: where x can be 2, 3, 4, 9, 10 or 11 to select the TIM peripheral.
  * @param  TIM_ICPSC: specifies the Input Capture1 prescaler new value.
  *   This parameter can be one of the following values:
  *     @arg TIM_ICPSC_DIV1: no prescaler
  *     @arg TIM_ICPSC_DIV2: capture is done once every 2 events
  *     @arg TIM_ICPSC_DIV4: capture is done once every 4 events
  *     @arg TIM_ICPSC_DIV8: capture is done once every 8 events
  * @retval None
  */
void TIM_SetIC1Prescaler(TIM_TypeDef* TIMx, uint16_t TIM_ICPSC)
{
  /* Check the parameters */
  assert_param(IS_TIM_LIST1_PERIPH(TIMx));
  assert_param(IS_TIM_IC_PRESCALER(TIM_ICPSC));
  
  /* Reset the IC1PSC Bits */
  TIMx->CCMR1 &= (uint16_t)~((uint16_t)TIM_CCMR1_IC1PSC);
  /* Set the IC1PSC value */
  TIMx->CCMR1 |= TIM_ICPSC;
}

/**
  * @brief  Sets the TIMx Input Capture 2 prescaler.
  * @param  TIMx: where x can be 2, 3, 4 or 9 to select the TIM peripheral.
  * @param  TIM_ICPSC: specifies the Input Capture2 prescaler new value.
  *   This parameter can be one of the following values:
  *     @arg TIM_ICPSC_DIV1: no prescaler
  *     @arg TIM_ICPSC_DIV2: capture is done once every 2 events
  *     @arg TIM_ICPSC_DIV4: capture is done once every 4 events
  *     @arg TIM_ICPSC_DIV8: