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]

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.