STM32F4 Timer External Clock TI2 Both Edges Demo

#define CLK_FREQ    ( 10000 )
#define CORE_FREQ   ( 168000000 )

static void TIM_GPIO_Config( void )
{
  GPIO_InitTypeDef GPIO_InitStructure;

  // Enable GPIOA clock
  __HAL_RCC_GPIOA_CLK_ENABLE( );

  // Configure PA8 pin as CLK output -- to CK Input
  GPIO_InitStructure.Mode = GPIO_MODE_AF_PP;
  GPIO_InitStructure.Pull = GPIO_NOPULL;
  GPIO_InitStructure.Pin = GPIO_PIN_8;
  GPIO_InitStructure.Speed = GPIO_SPEED_HIGH;
  GPIO_InitStructure.Alternate = GPIO_AF1_TIM1;

  HAL_GPIO_Init( GPIOA, &GPIO_InitStructure );

  // Enable GPIOC clock
  __HAL_RCC_GPIOC_CLK_ENABLE( );

  // Configure PC7 pin as CK input -- from CLK Output
  // Can not uses GPIO_MODE_INPUT : AF = 0
  GPIO_InitStructure.Mode = GPIO_MODE_AF_PP; // AF = 3
  GPIO_InitStructure.Pull = GPIO_NOPULL;
  GPIO_InitStructure.Pin = GPIO_PIN_7;
  GPIO_InitStructure.Speed = GPIO_SPEED_HIGH;
  GPIO_InitStructure.Alternate = GPIO_AF3_TIM8;
  HAL_GPIO_Init( GPIOC, &GPIO_InitStructure );

  // Configure PC6 pin as CK output -- to Oscilloscope Display
  GPIO_InitStructure.Mode = GPIO_MODE_AF_PP;
  GPIO_InitStructure.Pull = GPIO_NOPULL;
  GPIO_InitStructure.Pin = GPIO_PIN_6;
  GPIO_InitStructure.Speed = GPIO_SPEED_HIGH;
  GPIO_InitStructure.Alternate = GPIO_AF3_TIM8;
  HAL_GPIO_Init( GPIOC, &GPIO_InitStructure );
}

TIM_HandleTypeDef TimHandle;
TIM_MasterConfigTypeDef sMasterConfig;
TIM_SlaveConfigTypeDef sSlaveConfig;

TIM_OC_InitTypeDef sConfig;

static void Error_Handler( void )
{
  while ( 1 )
  {
  }
}

void TIM_CLK_Output( void )
{
  __HAL_RCC_TIM1_CLK_ENABLE( )
  ;

  TimHandle.Instance = TIM1;

  TimHandle.Init.Period = 1;
  TimHandle.Init.Prescaler = CORE_FREQ / CLK_FREQ - 1;
  TimHandle.Init.ClockDivision = 0;
  TimHandle.Init.CounterMode = TIM_COUNTERMODE_UP;
  if ( HAL_TIM_PWM_Init( &TimHandle ) != HAL_OK )
    Error_Handler( );

  sConfig.OCMode = TIM_OCMODE_PWM1;
  sConfig.OCPolarity = TIM_OCPOLARITY_HIGH;
  sConfig.OCFastMode = TIM_OCFAST_DISABLE;
  sConfig.Pulse = 1;
  if ( HAL_TIM_PWM_ConfigChannel( &TimHandle, &sConfig, TIM_CHANNEL_1 ) != HAL_OK )
    Error_Handler( );

  if ( HAL_TIM_PWM_Start( &TimHandle, TIM_CHANNEL_1 ) != HAL_OK )
    Error_Handler( );
}

void TIM_CK_Input( void )
{
  __HAL_RCC_TIM8_CLK_ENABLE( );

  TimHandle.Instance = TIM8;

  TIM_IC_InitTypeDef IC_InitTypeDef;
  IC_InitTypeDef.ICFilter = 0;
  IC_InitTypeDef.ICPolarity = TIM_ICPOLARITY_BOTHEDGE;
  IC_InitTypeDef.ICPrescaler = TIM_ICPSC_DIV1;
  IC_InitTypeDef.ICSelection = TIM_ICSELECTION_DIRECTTI; // TIM8_CH2 : PC7
  HAL_TIM_IC_ConfigChannel( &TimHandle, &IC_InitTypeDef, TIM_CHANNEL_2 );

  TIM_ClockConfigTypeDef ClockConfig;
  ClockConfig.ClockFilter = 0;
  ClockConfig.ClockPolarity = TIM_CLOCKPOLARITY_BOTHEDGE;
  ClockConfig.ClockPrescaler = TIM_CLOCKPRESCALER_DIV1;
  ClockConfig.ClockSource = TIM_CLOCKSOURCE_TI2; // TIM8_CH2 : PC7
  HAL_TIM_ConfigClockSource( &TimHandle, &ClockConfig );

  TimHandle.Init.Period = 1;
  TimHandle.Init.Prescaler = 0;
  TimHandle.Init.ClockDivision = 0;
  TimHandle.Init.CounterMode = TIM_COUNTERMODE_UP;
  if ( HAL_TIM_Base_Init( &TimHandle ) != HAL_OK )
    Error_Handler( );

  if ( HAL_TIM_Base_Start( &TimHandle ) != HAL_OK )
    Error_Handler( );
}

void TIM_CK_Output( void )
{
  TimHandle.Instance = TIM8;

  sConfig.OCMode = TIM_OCMODE_PWM1;
  sConfig.OCPolarity = TIM_OCPOLARITY_LOW; // Inverted CK_Input
  sConfig.OCFastMode = TIM_OCFAST_DISABLE;
  sConfig.Pulse = 1;
  if ( HAL_TIM_PWM_ConfigChannel( &TimHandle, &sConfig, TIM_CHANNEL_1 ) != HAL_OK )
    Error_Handler( );

  if ( HAL_TIM_PWM_Start( &TimHandle, TIM_CHANNEL_1 ) != HAL_OK )
    Error_Handler( );
}

void Timer_Demo( void )
{
  TIM_GPIO_Config( );
  TIM_CLK_Output( );  // To CK_Input 5 KHz
  TIM_CK_Input( );    // From CLK_Output 5 KHz
  TIM_CK_Output( );   // PWM Output 5 KHz -- Inverted CL_Output with Delay

  while ( 1 )
  {
  }
}