基于TMS320F2812，实时捕捉外部输入信号的频率，并可根据CPA1捕获结果按开发者意愿灵活调整PWM1输出方波的频率和占空比。-The program runs on DSP TMS320F2812, captures the frequency of external signal by real-time, and modifies output signal PWM1 s frequency and duty cycles according to the developer s n