/*!
    \file    readme.txt
    \brief   description of TRIGSEL select an extinput as trigger source to trigger TIMER1 example

    \version 2025-08-09, V1.7.0, firmware for GD32A50x
*/

/*
    Copyright (c) 2025, GigaDevice Semiconductor Inc.

    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 the copyright holder 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, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 
ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY 
OF SUCH DAMAGE.
*/

  This example is based on the GD32A503V-EVAL-V1.1 board,  it shows how to start TIMER 
peripherals with TRIGSEL. TRIGSEL select an external signal(TRIGSEL_IN0) as trigger source 
to TIMER1_ITI0, The TIMER1_ITI0 is used as TIMER1 input trigger. 

  TIMER1 is configured as slave timer:
  - Rising edge is used to start the TIMER1: trigger mode.
  - TIMER1 is used PWM0 Mode
  The starts of the TIMER1 counter are controlled by the TRIGSEL trigger.

  connect TRIGSEL_IN0(PA1) from GND to +3V3 on the board as a external trigger with
a rising edge.
