/**
@page TIM_OCActive TIM_OCActive example
@verbatim
******************** (C) COPYRIGHT 2017 STMicroelectronics *******************
* @file TIM/TIM_OCActive/readme.txt
* @author MCD Application Team
* @brief This example shows how to configure the Timer to generate four
* delayed signals.
******************************************************************************
* @attention
*
* Copyright (c) 2017 STMicroelectronics.
* All rights reserved.
*
* This software is licensed under terms that can be found in the LICENSE file
* in the root directory of this software component.
* If no LICENSE file comes with this software, it is provided AS-IS.
*
******************************************************************************
@endverbatim
@par Example Description
This example shows how to configure the TIM peripheral in Output Compare Active
mode (when the counter matches the capture/compare register, the concerned output
pin is set to its active state).
The TIM3 frequency is set to SystemCoreClock, and the objective is
to get TIM3 counter clock at 10 kHz so the Prescaler is computed as following:
- Prescaler = (TIM3CLK /TIM3 counter clock) - 1
SystemCoreClock is set to 100 MHz for STM32F413xx/STM32F423xx Devices.
The TIM3 CCR1 register value is equal to 10000:
TIM3_CH1 delay = CCR1_Val/TIM3 counter clock = 1s
so the TIM3 Channel 1 generates a signal with a delay equal to 1s.
The TIM3 CCR2 register value is equal to 5000:
TIM3_CH2 delay = CCR2_Val/TIM3 counter clock = 500 ms
so the TIM3 Channel 2 generates a signal with a delay equal to 500 ms.
The TIM3 CCR3 register value is equal to 2500:
TIM3_CH3 delay = CCR3_Val/TIM3 counter clock = 250 ms
so the TIM3 Channel 3 generates a signal with a delay equal to 250 ms.
The TIM3 CCR4 register value is equal to 1250:
TIM3_CH4 delay = CCR4_Val/TIM3 counter clock = 125 ms
so the TIM3 Channel 4 generates a signal with a delay equal to 125 ms.
The delay correspond to the time difference between PB.07 rising edge and
TIM3_CHx signal rising edges. PB.07 is connected to pin21 in CN11 connector.
@note Delay values mentioned above are theoretical (obtained when the system clock frequency
is exactly 100 MHz). Since the generated system clock frequency may vary from one board to another observed
delay might be slightly different.
@note Care must be taken when using HAL_Delay(), this function provides accurate delay (in milliseconds)
based on variable incremented in SysTick ISR. This implies that if HAL_Delay() is called from
a peripheral ISR process, then the SysTick interrupt must have higher priority (numerically lower)
than the peripheral interrupt. Otherwise the caller ISR process will be blocked.
To change the SysTick interrupt priority you have to use HAL_NVIC_SetPriority() function.
@note The application need to ensure that the SysTick time base is always set to 1 millisecond
to have correct HAL operation.
@par Keywords
Timers, Output, Compare, Active, Signals
@par Directory contents
- TIM/TIM_OCActive/Inc/stm32f4xx_hal_conf.h HAL configuration file
- TIM/TIM_OCActive/Inc/stm32f4xx_it.h Interrupt handlers header file
- TIM/TIM_OCActive/Inc/main.h Header for main.c module
- TIM/TIM_OCActive/Src/stm32f4xx_it.c Interrupt handlers
- TIM/TIM_OCActive/Src/main.c Main program
- TIM/TIM_OCActive/Src/stm32f4xx_hal_msp.c HAL MSP file
- TIM/TIM_OCActive/Src/system_stm32f4xx.c STM32F4xx system source file
@par Hardware and Software environment
- This example runs on STM32F413xx/STM32F423xx devices.
- This example has been tested with STMicroelectronics NUCLEO-F413ZH
board and can be easily tailored to any other supported device
and development board.
- NUCLEO-F413ZH Set-up
Connect the following pins to an oscilloscope to monitor the different waveforms:
- Use LED2 connected to PB.07 (Reference)
- PB.04: (TIM3_CH1) (connected to PB.04 (pin 19 in CN7 connector))
- PB.05: (TIM3_CH2) (connected to PB.05 (pin 13 in CN7 connector))
- PB.00: (TIM3_CH3) (connected to PB.00 (pin 31 in CN10 connector))
- PB.01: (TIM3_CH4) (connected to PB.01 (pin 7 in CN10 connector))
@par How to use it ?
In order to make the program work, you must do the following :
- Open your preferred toolchain
- Rebuild all files and load your image into target memory
- Run the example
*/
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