/*!
    \file    readme.txt
    \brief   description of DMA request synchronization example

    \version 2026-03-04, V1.0.0, firmware for GD32M53x
*/

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*/

  This example is based on the GD32M531R-EVAL-V1.2 board, it provides a description
of how to use DMAMUX request multiplexer channel 0 synchronization mode for DMA
transmission.
  In this demo, DMA channel 0 is configured to transfer data from memory to peripheral.
DMAMUX request multiplexer channel 0 is configured as synchronization mode, using EXTI_0
line rising edge to start 4 DMA requests transferring to DMA controller.
  The steps are shown as follows:
  1. At the start, users press the Wakeup key to start 4 DMA requests transferring. The DMA
     controller will transfer data from memory to UART3 TX register.
  2. Repeat several times to press the Wakeup key to start another 4 DMA requests transferring
     until all the data are  transferred to UART3 TX register. When all data are  transferred,
     a DMA transfer complete interrupt will occur.
  3. If the transfer is successful, LED1 will be on.
