88 lines
3.3 KiB
Plaintext
88 lines
3.3 KiB
Plaintext
/**
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@page TIM_DMA TIM DMA example
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@verbatim
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******************** (C) COPYRIGHT 2016 STMicroelectronics *******************
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* @file TIM/TIM_DMA/readme.txt
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* @author MCD Application Team
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* @brief Description of the TIM DMA example.
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******************************************************************************
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* @attention
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*
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* <h2><center>© Copyright (c) 2016 STMicroelectronics.
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* All rights reserved.</center></h2>
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*
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* This software component is licensed by ST under BSD 3-Clause license,
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* the "License"; You may not use this file except in compliance with the
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* License. You may obtain a copy of the License at:
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* opensource.org/licenses/BSD-3-Clause
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*
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******************************************************************************
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@endverbatim
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@par Example Description
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Use of the DMA with TIMER Update request
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to transfer data from memory to TIMER Capture Compare Register 3 (TIM1_CCR3).
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The following configuration values are used in this example:
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- TIM1CLK = SystemCoreClock
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- Counter repetition = 3
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- Prescaler = 0
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- TIM1 counter clock = SystemCoreClock
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- SystemCoreClock is set to 64 MHz for STM32F1xx
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The objective is to configure TIM1 channel 3 to generate complementary PWM
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(Pulse Width Modulation) signal with a frequency equal to 17.57 KHz, and a variable
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duty cycle that is changed by the DMA after a specific number of Update DMA request.
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The number of this repetitive requests is defined by the TIM1 Repetition counter,
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each 4 Update Requests, the TIM1 Channel 3 Duty Cycle changes to the next new
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value defined by the aCCValue_Buffer.
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The PWM waveform can be displayed using an oscilloscope.
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@note Care must be taken when using HAL_Delay(), this function provides accurate
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delay (in milliseconds) based on variable incremented in SysTick ISR. This
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implies that if HAL_Delay() is called from a peripheral ISR process, then
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the SysTick interrupt must have higher priority (numerically lower)
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@note The application need 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 Directory contents
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- TIM/TIM_DMA/Inc/stm32f1xx_hal_conf.h HAL configuration file
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- TIM/TIM_DMA/Inc/stm32f1xx_it.h Interrupt handlers header file
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- TIM/TIM_DMA/Inc/main.h Header for main.c module
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- TIM/TIM_DMA/Src/stm32f1xx_it.c Interrupt handlers
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- TIM/TIM_DMA/Src/main.c Main program
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- TIM/TIM_DMA/Src/stm32f1xx_hal_msp.c HAL MSP file
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- TIM/TIM_DMA/Src/system_stm32f1xx.c STM32F1xx system source file
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@par Hardware and Software environment
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- This example runs on STM32F103RB devices.
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- In this example, the clock is set to 64 MHz.
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- This example has been tested with STMicroelectronics STM32F103RB-Nucleo
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board and can be easily tailored to any other supported device
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and development board.
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- STM32F103RB-Nucleo Set-up
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- Connect the TIM1 pin to an oscilloscope to monitor the different waveforms:
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- TIM1 CH3 (PA.10)
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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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* <h3><center>© COPYRIGHT STMicroelectronics</center></h3>
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*/
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