内附多路选择器，74系列芯片VHDL源码，加法器，FIR，比较器等大量例子，对初学VHDL语言很有好处。可用maxplus，quartus，synplicity...

使用VHDL语言实现对快速傅立叶变换算法的实现，并通过仿真验证其正确性。(Using VHDL language implementation for the realization of fast Fourier transform algorithm, and its correctness is validated by computer simulation.)

1、 利用FLEX10的片内RAM资源，根据DDS原理，设计产生正弦信号的各功能模块和顶层原理图； 2、 利用实验板上的TLC7259转换器，将1中得到的正弦信号，通过D/A转换，通过ME5534滤波后在示波器上观察； 3、 输出波形要求： 在输入时钟频率为16KHz时，输出正弦波分辨率达到1Hz； 在输入时钟频率为4MHz时，输出正弦波分辨率达到256Hz； 4、 通过RS232C通信，实现FPGA和PC机之间串行通信，从而实现用PC机改变频率控制字，实现对输出正弦波频率的控制。-a use FLEX10-chip RAM resources, in accordance with DDS principle, design sinusoidal signal generated by the top-level functional modules and schematics; 2, the experimental board TLC7259 converters, will be a sinusoidal signal, the D/A conversion, after filtering through the ME5534 oscilloscope observation; 3, the output waveform requirements : the input clock frequency of 16KHz, sine wave output resolution of 1Hz; the input clock frequency of 4MHz, the sine wave output resolution of 256Hz; 4, RS232C communications, FPGA and PC serial communications between in order to achieve PC-frequency control characters, the realization of sine wave output frequency control.

51数字钟带各种扩展年，月，日等并且可预置。用汇编语言写的(51 digital clock with extended assembly language)

说明：  用FPGA实现8点fft，整个代码使用verilog编写，主要运用了加法器和乘法器，简单易懂(8-point FFT with FPGA, The whole code is written by Verilog, mainly using adder and multiplier, which is easy to understand)

基于quartus的3-8译码器,可作为大型系统的译码器模块-Based on quartus a 3-8 decoder can be used as large-scale system decoder module

spartan 3 hardware reference document xilinx

Code VHDL for control VGA FPGA: Xilinx, Altera

实现pwm波的输出，按键可调占空比的，可通过连接pwm输出值led灯以检测占空比的变化(To realize the output of the PWM wave, key adjustable duty ratio, but through the connection PWM output value led lamp with testing duty ratio changes )

将VHDL程序下载到DE2开发板，引脚分配时需要知道的芯片每个引脚功能(VHDL program will be downloaded to the DE2 development board, you need to know when the pin assignments for each pin of the chip functions)

本代码实现了全加器的功能，可供初学者学习-This code implements a full adder functions, for beginners to learn