使用vhdl语言在quatus上编写自定义元件，用原理图实现了蜂鸣器按照音阶一秒换一个音进行循环发声，系统时钟为20m。(Using the VHDL language to write a custom component on the quatus, the buzzer is used to make a circular sound in one second of the phonetic scale, and the system clock is 20m.)

PowerFilter is a powerful, easy-to-implement datawindow filtering component that provides users functionality similar to what is found in Excel. Add one control to your window and 3 lines of Powerscr ipt to implement.

基于FFT的谐波检测,采用快速傅里叶算法后得到原始波形中各次分量的频率和幅值特性，从中可以直接观测出各次谐波分量的频率和幅值信息. 程序1采用快速傅里叶算法后得到原始波形中各次分量的频率和幅值特性图 程序2输入信号经过FFT变换得到的频谱特性图 程序3对输入信号进行采样，应用一维小波变换函数进行三层小波分析(Based on FFT harmonic detection, the frequency and amplitude characteristics of each harmoni