fpga clock design, the information is better, for your reference, non

是一个用vhdl语言编写的pwm程序，可以方便地用来和nios连接，实现对nios的功能扩展。-is a VHDL language with the PWM procedures can be used to facilitate connections and nios, nios to achieve a functional extension.

VHDL的动态扫描显示六个数码管，包含分频代码产生25kHz的扫描信号作为时钟。(VHDL dynamic scanning display six digital tube contains 25kHz scanning signal is generated as a clock divider code.)

实现arm与fpga之间通过gpmc总线通信(the device of fpga)

利用IIC接口的4路 ADC max1037，采集思路信号，通过在FPGA内部的构建DeltaSigma DAC软核，在VGA液晶显示屏上显示波形。 (IIC interface 4-way ADC max1037, collecting ideas signal the FPGA internal build DeltaSigma DAC soft-core VGA LCD display waveforms.)

说明：  直接数字式频率合成器DDS设计、Verilog。 产生的信号可以是正弦波或方波、三角波、锯齿波等，自选。 采用DDS技术，将所需生成的波形写入ROM中，按照相位累加原理合成任意波形。 此方案得到的波形稳定，精度高，产生波形频率范围大，容易产生高频。 本实验在设计的模块中，包含以下功能： （1）通过 freq 信号输入需要的频率的值； （2）通过 wave_sel 信号选择所需的波形； （3）通过 amp_adj 信号选择波形放大的倍数。(DDS design of direct digital frequency synthesizer, Verilog. The generated signal can be sinusoidal or square wave, triangular wave, sawtooth wave and so on, optional. By using DDS technology, the required waveforms are written into ROM, and arbitrary waveforms are synthesized according to the principle of phase accumulation. The waveform obtained by this scheme is stable, accurate and easy to generate high frequency waveform. This experiment includes the following functions in the designed module: (1) Input the required frequency value through freq signal; (2) Choosing the required waveform by wave_sel signal; (3) Select the multiplier of waveform amplification by amp_adj signal.)

说明：  鉴于stm32在keil平台上的ADC采集转化，在LCD屏上显示程序(voltage acquisition adc)

说明：  高清电子书4本合集-Verilog HDL数字系统设计教程4本合集(Digital circuit design Verilog HDL digital system design)

数字电路与逻辑设计实验编程，包含多功能电子钟程序，实用，简易(Digital circuits and logic design experiments programming, including multi-function electronic clock procedures, practical, simple)

利用LMP的20bit counter,比自带的cout进位要快的多。已经同错综合和时序仿真。-LMP

说明：  使用ISE软件实现OFDM通信系统的框架搭建，完成上板前的仿真工作(Realization of OFDM communication system with ISE software)