1. 功能说明
    USB HID 键盘设备

2. 使用环境
    硬件环境：工程对应的开发硬件平台 
    开发板：   N32G4XM-STB V1.1

3. 使用说明
    描述相关模块配置方法；例如:时钟，I/O等 
         1. SystemClock：144MHz
         2. USBClock: 48MHz
         3. GPIO：PC7 键盘输入

    描述Demo的测试步骤和现象 
         1. 编译后下载程序复位运行；
         2. 通过 USB 线连接 J3 USB 口，电脑识别出键盘设备，PC7 接地，USB 输入 "a"。

4. 注意事项
    无

1. Function description
    USB HID keyboard device

2. Use environment
    Hardware environment: development hardware platform corresponding to the project 
    Development board:      N32G4XM-STB V1.1

3. Instructions for use
    Describe the configuration method of related modules; for example: clock, I/O, etc. 
        1. SystemClock: 144MHz
        2. USBClock: 48MHz
        3. GPIO: PC7 keyboard input
                  
    Describe the test steps and phenomena of Demo 
        1. After compiling, download the program to reset and run;
        2. Connect the J3 USB port through a USB cable, the computer recognizes the keyboard device, PC7 is grounded, and USB input "a".
 
4. Matters needing attention
    None.