1. Function description

1. This example shows how to read the high and low levels of the port and control the blinking of the LEDs (D1, D2, D3)
2. Control the IO port level flip


2. Use environment

/* Hardware environment: the development hardware platform corresponding to the project */
Development board: N32L43XM-STB N32L40XM-STB V1.1

3. Instructions for use

/* Describe the configuration method of related modules; for example: clock, I/O, etc. */
1. SystemClock: 108MHz
2. GPIO: PA8, PB4, PB5 control LED (D1, D2, D3) blinking


/* Describe the test steps and phenomena of Demo */
1. After compiling, download the program to reset and run;
2. After power on, D1 is always on, D2 and D3 are flashing;


4. Matters needing attention
	without