GD32F3x0_Firmware_Library/Examples/EXTI/Key_external_interrupt_mode/readme.txt

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

/*
    Copyright (C) 2017 GigaDevice

    2017-06-06, V1.0.0, firmware for GD32F3x0
*/

  This demo is based on the GD32350R-EVAL board, it shows how to generate 
the interrupt request, and toggle the LED. After the system start-up, LED1 
is on. When Tamper Key is pressed, LED2 is toggled, it is switched on; when 
Tamper Key is pressed once again, LED2 is toggled, it is switched off.