1、功能说明
    1、通过EXTI线来触发时间戳。

2、使用环境

    软件开发环境：KEIL MDK-ARM V5.34.0.0
                  IAR EWARM 8.50.1
    硬件环境：基于评估板N32G401C8L7-STB V1.0开发

3、使用说明
    
    系统配置:
        1、RTC时钟源：LSE 32.768kHz
        2、EXTI中断引脚：PB8
        3、串口配置：
                    - 串口为USART1（TX：PA9）:
                    - 数据位：8
                    - 停止位：1
                    - 奇偶校验：无
                    - 波特率： 115200 
    使用方法：
        编译后烧录到评估板，把PC13连接到PB8，上电后，串口每隔1S会打印时间戳输出。

4、注意事项
    无


1. Function description
    1. Trigger the timestamp through the EXTI line
    
2. Use environment
    Software development environment: KEIL MDK-ARM V5.34.0.0
                                      IAR EWARM 8.50.1
    Hardware environment: Developed based on the evaluation board N32G401C8L7-STB V1.0​

3. Instructions for use

    System Configuration;
        1. RTC clock source: LSE  32.768kHz
        2. EXTI interrupt IO: PB8
        3. Serial port configuration:
                            - Serial port is USART1 (TX: PA9)
                            - Data bits: 8
                            - Stop bit: 1
                            - Parity: none
                            - Baud rate: 115200


    Instructions:
        After compiling, burn it to the evaluation board, connect PC13 to PB8, after power-on, the serial port will print timestamp output every 1S.


4. Attention
    none