SPI clock use as a timer

[pshin.2]

Hii,

I am using STM32h745IIK6. I want to use my SPI clock as a timer to generate delay in microsecond how can i to that. Please help with tutorial or your guidance.  Thanks in advance.

[FBL · Accepted solution]

Hello @pshin.2, 

You can synchronize the SPI clock and Timer input pin. Here is an example to get started with.

  /*##- Configure the SPI peripheral with the desired frequency #######################################
...

  /*##- Configure the TIM peripheral #######################################
   *
  *-The external signal is connected to TIM4_CH2 pin (PB.07),
  * and a rising edge on this input is used to trigger the Timer.
  *
  *-The One Pulse signal is output on TIM4_CH1 (PB.06).
  *
  * The delay value is fixed to:
  * - Delay =  CCR1/TIM4 counter clock
  *          = 16383 / 20000000 [sec]
  *
  * The pulse value is fixed to :
  * - Pulse value = (TIM_Period - TIM_Pulse)/TIM4 counter clock
  *               = (65535 - 16383) / 20000000 [sec]
  *
  * ------------------------------------------------------------------------ */
 /* Enable the TIMx clock */
 TIMx_CLK_ENABLE();

 /* Enable GPIO Port Channel1 & channel2 Clock */
 TIMx_CHANNEL_GPIO_PORT();

 /* Configure PB.06 and PB.07 */
 GPIO_InitStruct.Mode = GPIO_MODE_AF_PP;
 GPIO_InitStruct.Speed = GPIO_SPEED_FREQ_HIGH;
 GPIO_InitStruct.Alternate = GPIO_AF_TIMx;

 GPIO_InitStruct.Pull = GPIO_PUPD_CHANNEL1;
 GPIO_InitStruct.Pin = GPIO_PIN_CHANNEL1;
 HAL_GPIO_Init(TIMx_GPIO_PORT, &GPIO_InitStruct);

 GPIO_InitStruct.Pull = GPIO_PUPD_CHANNEL2;
 GPIO_InitStruct.Pin = GPIO_PIN_CHANNEL2;
 HAL_GPIO_Init(TIMx_GPIO_PORT, &GPIO_InitStruct);



TimHandle.Instance = TIMx;

 TimHandle.Init.Period            = 0xFFFF;
 TimHandle.Init.Prescaler         = uwPrescalerValue;
 TimHandle.Init.ClockDivision     = 0;
 TimHandle.Init.CounterMode       = TIM_COUNTERMODE_UP;
 TimHandle.Init.RepetitionCounter = 0;

 if (HAL_TIM_OnePulse_Init(&TimHandle, TIM_OPMODE_SINGLE) != HAL_OK)
 {
   /* Initialization Error */
   Error_Handler();
 }

 /*##-2- Configure the Channel 1 in One Pulse mode ##########################*/
 sConfig.OCMode       = TIM_OCMODE_PWM2;
 sConfig.OCPolarity   = TIM_OCPOLARITY_HIGH;
 sConfig.Pulse        = 16383;
 sConfig.ICPolarity   = TIM_ICPOLARITY_RISING;
 sConfig.ICSelection  = TIM_ICSELECTION_DIRECTTI;
 sConfig.ICFilter     = 0;
 sConfig.OCNPolarity  = TIM_OCNPOLARITY_HIGH;
 sConfig.OCIdleState  = TIM_OCIDLESTATE_RESET;
 sConfig.OCNIdleState = TIM_OCNIDLESTATE_RESET;

 if (HAL_TIM_OnePulse_ConfigChannel(&TimHandle, &sConfig, TIM_CHANNEL_1, TIM_CHANNEL_2) != HAL_OK)
 {
   /* Configuration Error */
   Error_Handler();
 }

  if (HAL_TIM_OnePulse_Start(&TimHandle, TIM_CHANNEL_1) != HAL_OK)
 {
   /* Starting Error */
   Error_Handler();
 }

You can configure SPI peripheral with the desired clock frequency. You will also need to adjust the timer prescaler and period values to generate interrupts at the desired frequency.