88 lines
3.3 KiB
Plaintext
88 lines
3.3 KiB
Plaintext
/**
|
|
@page TIM_DMA TIM DMA example
|
|
|
|
@verbatim
|
|
******************** (C) COPYRIGHT 2016 STMicroelectronics *******************
|
|
* @file TIM/TIM_DMA/readme.txt
|
|
* @author MCD Application Team
|
|
* @brief Description of the TIM DMA example.
|
|
******************************************************************************
|
|
* @attention
|
|
*
|
|
* <h2><center>© Copyright (c) 2016 STMicroelectronics.
|
|
* All rights reserved.</center></h2>
|
|
*
|
|
* This software component is licensed by ST under BSD 3-Clause license,
|
|
* the "License"; You may not use this file except in compliance with the
|
|
* License. You may obtain a copy of the License at:
|
|
* opensource.org/licenses/BSD-3-Clause
|
|
*
|
|
******************************************************************************
|
|
@endverbatim
|
|
|
|
@par Example Description
|
|
|
|
Use of the DMA with TIMER Update request
|
|
to transfer data from memory to TIMER Capture Compare Register 3 (TIM1_CCR3).
|
|
|
|
The following configuration values are used in this example:
|
|
|
|
- TIM1CLK = SystemCoreClock
|
|
- Counter repetion = 3
|
|
- Prescaler = 0
|
|
- TIM1 counter clock = SystemCoreClock
|
|
- SystemCoreClock is set to 72 MHz for STM32F1xx
|
|
|
|
The objective is to configure TIM1 channel 3 to generate complementary PWM
|
|
(Pulse Width Modulation) signal with a frequency equal to 17.57 KHz, and a variable
|
|
duty cycle that is changed by the DMA after a specific number of Update DMA request.
|
|
|
|
The number of this repetitive requests is defined by the TIM1 Repetition counter,
|
|
each 4 Update Requests, the TIM1 Channel 3 Duty Cycle changes to the next new
|
|
value defined by the aCCValue_Buffer.
|
|
|
|
The PWM waveform can be displayed using an oscilloscope.
|
|
|
|
|
|
|
|
@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)
|
|
|
|
@note The application need to ensure that the SysTick time base is always set to 1 millisecond
|
|
to have correct HAL operation.
|
|
|
|
@par Directory contents
|
|
|
|
- TIM/TIM_DMA/Inc/stm32f1xx_hal_conf.h HAL configuration file
|
|
- TIM/TIM_DMA/Inc/stm32f1xx_it.h Interrupt handlers header file
|
|
- TIM/TIM_DMA/Inc/main.h Header for main.c module
|
|
- TIM/TIM_DMA/Src/stm32f1xx_it.c Interrupt handlers
|
|
- TIM/TIM_DMA/Src/main.c Main program
|
|
- TIM/TIM_DMA/Src/stm32f1xx_hal_msp.c HAL MSP file
|
|
- TIM/TIM_DMA/Src/system_stm32f1xx.c STM32F1xx system source file
|
|
|
|
@par Hardware and Software environment
|
|
|
|
- This example runs on STM32F103xG devices.
|
|
- In this example, the clock is set to 72 MHz.
|
|
|
|
- This example has been tested with STMicroelectronics STM3210E-EVAL RevD
|
|
board and can be easily tailored to any other supported device
|
|
and development board.
|
|
|
|
- STM3210E-EVAL RevD Set-up
|
|
- Connect the TIM1 pin to an oscilloscope to monitor the different waveforms:
|
|
- TIM1 CH3 (PA.10)
|
|
|
|
@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
|
|
|
|
* <h3><center>© COPYRIGHT STMicroelectronics</center></h3>
|
|
*/
|