1、功能说明
    1、TIM2周期门控TIM3，TIM3周期门控TIM4
2、使用环境
    软件开发环境：  KEIL MDK-ARM V5.26.2.0
    硬件环境：      基于N32L43XML-STB_V1.0开发
3、使用说明
    系统配置；
        1、时钟源：
            HSE=8M,PLL=108M,AHB=108M,APB1=27M,APB2=54M,TIM2 CLK=54M,TIM3 CLK=54M,TIM4 CLK=54M
        2、端口配置：
            PA0选择为TIM2 CH1输出
            PA6选择为TIM3 CH1输出
            PB6选择为TIM4 CH1输出
        3、TIM：
            TIM2 的周期门控TIM3，TIM3的周期门控TIM4
    使用方法：
        1、编译后打开调试模式，用示波器或者逻辑分析仪观察TIM2 CH1，TIM3 CH1，TIM4 CH1波形
        2、TIM3 4倍周期TIM2，TIM4 4倍周期TIM3
4、注意事项
    无

1. Function description
     1. TIM2 cycle gate TIM3, TIM3 cycle gate TIM4
2. Use environment
     Software development environment: KEIL MDK-ARM V5.26.2.0
     Hardware environment: Developed based on N32L43XML-STB_V1.0
3. Instructions for use
     System Configuration;
         1. Clock source:
             HSE=8M, PLL=108M, AHB=108M, APB1=27M, APB2=54M, TIM2 CLK=54M, TIM3 CLK=54M, TIM4 CLK=54M
         2. Port configuration:
             PA0 is selected as TIM2 CH1 output
             PA6 is selected as TIM3 CH1 output
             PB6 is selected as TIM4 CH1 output
         3. TIM:
             The period gate of TIM2 controls TIM3, the period gate of TIM3 controls TIM4
     Instructions:
         1. After compiling, turn on the debug mode, use an oscilloscope or logic analyzer to observe the waveforms of TIM2 CH1, TIM3 CH1, TIM4 CH1
         2. TIM3 4 times cycle TIM2, TIM4 4 times cycle TIM3
4. Matters needing attention
     without