VHDL 的4*4键盘代码

FPGA编写环境，具有仿真容易，软件内存小的特点(FPGA authoring environment, with easy simulation software features small memory)

说明：  In the data management system a significant role of the Data link layer is to convert the unreliable physical link between reader and tag into a reliable link. Therefore, the RFID system employs the Cyclic Redundancy Check (CRC) as an error detection scheme. In addition for reader to communicate with the multiple tags, an anti-collision technique is required. The technique is to coordinate the communication between the reader and the tags. The common deterministic anti-collision techniques are based on the Tree algorithm such as the Binary Tree and the Query Tree algorithms.

在quartus下搭建的数字锁相环，能实现频率自动跟踪。(The digital phase-locked loop built under quartus can realize automatic frequency tracking.)

讲述了全数字信号发生器部分频率值测算的表格(Full digital signal generator frequency value calculation form )

Top module name : SHIFTER (File name : SHIFTER.v) 2. Input pins: SHIFT [3:0], IN [15:0], SIGN, RIGHT. 3. Output pins: OUT [15:0]. 4. Input signals generated from test pattern are latched in one cycle and are synchronized at clock rising edge. 5. The SHIFT signal describes the shift number. The shift range is 0 to 15. 6. When the signal RIGHT is high, it shifts input data to right. On the other hand, it shifts input data to left. 7. When the signal SIGN is high, the input data is a signed number and it shifts with sign extension. However, the input data is an unsigned number if the signal SIGN is low. 8. You can only use following gates in Table I and need to include the delay information (Tplh, Tphl) in your design.

电子表，实现计时记分计秒的功能，同时可以对时分秒进行校正，实现调时功能。-Electronic watches, time points of dollars to achieve a second function, at the same time when the minutes and seconds can be calibrated to achieve when the transfer function.

使用vhdl语言实现对led的控制，还有电路仿真-Using vhdl language implementation of the led control, as well as circuit simulation

简单的Verilog程序，针对音频实验板的AD到DA调通试验，下载执行前请按照自己试验环境更改设置(Simple Verilog program for test the AD to DA loop of universal audio test platform. Please configure it according to the test environment before download and implement the program to FPGA)

用verilog编写的USB下载线程序 实现USB协议和JTAG接口的数据转换实现状态机-Verilog prepared using USB download cable program realize USB protocol and JTAG interface to achieve data conversion state machine

FPGA控制AD7321的模块，是本人亲自试验过的。有Verilog源码，和简单文档(Fpga control module of ad 7321, is I personally tested. Verilog source code, and simple documentation)