基于VHDL+FPGA的DDS信号发生设计，已经通过调式

说明：  设计一简易数字频率计，其基本要求是： 1)测量频率范围0～999999Hz； 2)最大读数999999HZ,闸门信号的采样时间为1s；. 3)被测信号可以是正弦波、三角波和方波； 4)显示方式为6位十进制数显示； 5）具有超过量程报警功能。 5)输入信号最大幅值可扩展。 6）测量误差小于+-0.1%。 7)完成全部设计后，可使用EWB进行仿真，检测试验设计电路的正确性。(The basic requirements of designing a simple digital frequency meter are: 1) The measuring frequency range is 0-999999 Hz. 2) The maximum reading is 999999HZ, and the sampling time of gate signal is 1 s. 3) The measured signal can be sine wave, triangle wave and square wave. 4) The display mode is 6-bit decimal number display. 5) It has alarm function beyond range. 5) The maximum amplitude of input signal can be expanded. 6) The measurement error is less than +0.1%. 7) After completing all the design, EWB can be used to simulate and test the correctness of the circuit.)

说明：  实现AD9117芯片的配置功能，这是一款DAC芯片(Realize the configuration function of ad9117 chip, which is a DAC chip)

基于VHDL编写的10进制显示输出，基于16进制的10进制控制，适合初学者(VHDL-based display output written in decimal, hexadecimal, 10 hexadecimal-based control, suitable for beginners)

这是一个16位乘法器Verilog程序，包括有符号位和无符号位乘法器(This is a 16-bit multiplier Verilog program, including the sign bit and no sign bit multiplier)

基于DB8小波变换的verilog代码设计，支持Avalon总线(Verilog DB8 Wavelet Transform Based on code design, support Avalon bus)

1024点fft verilog hdl(1024-point fft verilog hdl)

采用xilinx的ROMIP核产生类似正弦信号，经过FFt后可以观察结果(Using the xilinx ROMIP nuclear generating similar sinusoidal signal can be observed through the results after FFt)

4. If a modified source code is distributed, the original unmodified -- source code must also be included (or a link to the Free IP web -- site). In the modified source code there must be clear -- identification of the modified version.-4. If a modified source code is distributed, the original unmodified-- source code must also be included (or a link to the Free IP web-- site). In the modified source code there must be clear-- identification of the modified version.

very much verilog code for the beginner

Xilinx FPGA moving data across asynchronous clock boundaries