/**
  @page TIM_DMA TIM DMA example
  
  @verbatim
  ******************** (C) COPYRIGHT 2016 STMicroelectronics *******************
  * @file    TIM/TIM_DMA/readme.txt 
  * @author  MCD Application Team
  * @version V1.5.0
  * @date    14-April-2017
  * @brief   Description of the TIM DMA example.
  ******************************************************************************
  *
  * Redistribution and use in source and binary forms, with or without modification,
  * are permitted provided that the following conditions are met:
  *   1. Redistributions of source code must retain the above copyright notice,
  *      this list of conditions and the following disclaimer.
  *   2. Redistributions in binary form must reproduce the above copyright notice,
  *      this list of conditions and the following disclaimer in the documentation
  *      and/or other materials provided with the distribution.
  *   3. Neither the name of STMicroelectronics nor the names of its contributors
  *      may be used to endorse or promote products derived from this software
  *      without specific prior written permission.
  *
  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
  * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
  * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
  * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
  * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
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  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  *
  ******************************************************************************
  @endverbatim

@par Example Description 

  This example provides a description of how to use DMA with TIM1 Update request
  to transfer data from memory to TIM1 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>&copy; COPYRIGHT STMicroelectronics</center></h3>
 */
