1. 功能说明
    此例程展示 USB U 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：   N32WB45xL_EVB_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. USB Clock：48MHz
         3. GPIO：USART1：TX--PA9  RX--PA10，波特率：115200

    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 线连接口，USB 挂载完成后，电脑识别到一个U盘，格式化后可以打开U盘

4. 注意事项
    无

1. Function description
    This routine shows USB U disk device

2. Use environment
    Hardware environment: development hardware platform corresponding to the project 
    Development board:      N32WB45xL_EVB_V1.1

3. Instructions for use
    Describe the configuration method of related modules; for example: clock, I/O, etc. 
        1. SystemClock: 144MHz
        2. USB Clock: 48MHz
        3. GPIO: USART1: TX--PA9 RX--PA10 Baud rate: 115200

    Describe the test steps and phenomena of Demo 
        1. After compiling, download the program to reset and run;
        2. After the USB cable connection port, the USB mount is completed, the computer identifies a U disk, open the U disk after formatting

4. Matters needing attention
    None.