wenkong_junshi/Examples/FWDGT/FWDGT_key

/*!
\file readme.txt
\brief description of the FWDGT_key example

\version 2017-02-10, V1.0.0, firmware for GD32F30x
\version 2018-10-10, V1.1.0, firmware for GD32F30x
\version 2018-12-25, V2.0.0, firmware for GD32F30x
\version 2020-09-30, V2.1.0, firmware for GD32F30x
*/

/*
Copyright (c) 2020, GigaDevice Semiconductor Inc.

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*/

This demo is based on the GD32307C-EVAL-V1.1 board, it shows how to reload the
FWDGT counter at regulate period using the EXTI interrupt. The FWDGT timeout
is set to 1.6s (the timeout may varies due to IRC40K frequency dispersion).

An EXTI is connected to a specific GPIO pin and configured to generate an interrupt
on its falling edge: when the EXTI Line interrupt is triggered (by pressing the tamper
key on the board), the corresponding interrupt is served. In the ISR, FWDGT counter is
reloaded).

If the EXTI Line interrupt does not occur, the FWDGT counter is not reloaded before
the FWDGT counter reaches 00h, and the FWDGT reset.

There are three operation methods as follow:
1.After the download is completed and the system is powered on, LED2 flashes once and
then LED3 starts flashing.

2.After the download is completed and the system is powered on, start to press the tamper
button in quick succession, then LED2 is always on, and stop pressing the tamper button in
quick succession and LED3 starts to flash.

3.After the download is completed and the system is powered on, LED2 flashes once and then
LED3 starts flashing. At this time, after pressing the tamper button in rapid succession,
LED3 is always on, and after stopping the rapid and continuous pressing of the tamper button,
LED3 starts flashing