/*!
\file readme.txt
\brief description of the FWDGT_key example
\version 2021-10-30, V1.0.0, firmware for GD32W51x
*/
/*
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*/
This example is based on the GD32W515P-EVAL-V1.0 board, it shows how to reload the
FWDGT counter at regulate period using the EXTI interrupt. The FWDGT timeout
is set to 1s (the timeout may varies due to IRC32K 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/Wakeup
Key on the board), the corresponding interrupt is served. In the ISR, FWDGT counter is
reloaded). As a result, when the FWDGT counter is reloaded, which prevents any FWDGT reset,
LED2 off and LED1 on.
If the EXTI Line interrupt does not occur, the FWDGT counter is not reloaded before
the FWDGT counter reaches 00h, and the FWDGT reset, then LED1 and LED2 are turned off with
the system reset. FWDGTRST flag is set by hardware, and then LED2 is turned on.
