
1. Function description
    1. This routine shows IO level flipping quickly
2. Use environment
    Software development environment: KEIL MDK-ARM V5.30.0.0
    Hardware environment: Developed based on the development board N32WB031_STB

3. Instructions for use
    System Configuration;
        1. SystemClock: HSI 64MHz
        2. GPIO: the level of the PA0 pin flips quickly

    Instructions:
        1. After compiling, download the program to reset and run
        2. Use an oscilloscope to see the PA0 pin level flips quickly
4. Matters needing attention
    Null
