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105 lines
4.2 KiB
Plaintext
105 lines
4.2 KiB
Plaintext
/**
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@page TIM_OCInactive TIM Output Compare Active example
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@verbatim
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******************** (C) COPYRIGHT 2017 STMicroelectronics *******************
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* @file TIM/TIM_OCActive/readme.txt
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* @author MCD Application Team
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* @brief This example shows how to configure the Timer to generate four
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* delayed signals.
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******************************************************************************
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* @attention
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*
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* Copyright (c) 2017 STMicroelectronics.
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* All rights reserved.
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*
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* This software is licensed under terms that can be found in the LICENSE file
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* in the root directory of this software component.
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* If no LICENSE file comes with this software, it is provided AS-IS.
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*
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******************************************************************************
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@endverbatim
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@par Example Description
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This example shows how to configure the TIM peripheral in Output Compare Inactive
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mode with the corresponding Interrupt requests for each channel.
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The TIM2CLK frequency is set to SystemCoreClock / 2 (Hz), and the objective is
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to get TIM2 counter clock at 2 KHz so the Prescaler is computed as following:
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- Prescaler = (TIM2CLK / TIM2 counter clock) - 1
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SystemCoreClock is set to 180 MHz for STM32F4xx devices
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The TIM2 CCR1 register value is equal to 1000:
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TIM2_CC1 delay = CCR1_Val/TIM2 counter clock = 500 ms
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so the PA.00 is reset after a delay equal to 500 ms.
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The TIM2 CCR2 register value is equal to 500:
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TIM2_CC2 delay = CCR2_Val/TIM2 counter clock = 250 ms
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so the PA.01 is reset after a delay equal to 250 ms.
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The TIM2 CCR3 register value is equal to 250:
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TIM2_CC3 delay = CCR3_Val/TIM2 counter clock = 125 ms
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so the PA.02 is reset after a delay equal to 125 ms.
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The TIM2 CCR4 register value is equal to 125:
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TIM2_CC4 delay = CCR4_Val/TIM2 counter clock = 62.5 ms
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so the PA.03 is reset after a delay equal to 62.5 ms.
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While the counter is lower than the Output compare registers values, which
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determines the Output delay, the PG.06, PG.07, PG.10 and PG.12 pin are turned ON.
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When the counter value reaches the Output compare registers values, the Output
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Compare interrupts are generated and, in the handler routine, these pins are turned OFF.
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@note Care must be taken when using HAL_Delay(), this function provides accurate delay (in milliseconds)
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based on variable incremented in SysTick ISR. This implies that if HAL_Delay() is called from
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a peripheral ISR process, then the SysTick interrupt must have higher priority (numerically lower)
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than the peripheral interrupt. Otherwise the caller ISR process will be blocked.
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To change the SysTick interrupt priority you have to use HAL_NVIC_SetPriority() function.
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@note The application needs to ensure that the SysTick time base is always set to 1 millisecond
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to have correct HAL operation.
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@par Keywords
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Timers, Output, Compare, InActive, Signals, Delay, Frequency
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@par Directory contents
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- TIM/TIM_OCInactive/Inc/stm32f4xx_hal_conf.h HAL configuration file
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- TIM/TIM_OCInactive/Inc/stm32f4xx_it.h Interrupt handlers header file
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- TIM/TIM_OCInactive/Inc/main.h Main program header file
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- TIM/TIM_OCInactive/Src/stm32f4xx_it.c Interrupt handlers
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- TIM/TIM_OCInactive/Src/main.c Main program
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- TIM/TIM_OCInactive/Src/stm32f4xx_hal_msp.c HAL MSP module
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- TIM/TIM_OCInactive/Src/system_stm32f4xx.c STM32F4xx system clock configuration file
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@par Hardware and Software environment
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- This example runs on STM32F429xx/STM32F439xx devices.
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- This example has been tested with STMicroelectronics STM324x9I-EVAL RevB
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evaluation boards and can be easily tailored to any other supported device and development board
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- STM324x9I-EVAL RevB Set-up
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- Connect the following pins to an oscilloscope to monitor the different
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waveforms:
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- Use LED1 connected to PG.06
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- Use LED2 connected to PG.07
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- Use LED3 connected to PG.10
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- Use LED4 connected to PG.12
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@par How to use it ?
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In order to make the program work, you must do the following :
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- Open your preferred toolchain
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- Rebuild all files and load your image into target memory
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- Run the example
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*/
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