USB的vhdl代码，具有很强的指导意义，对FPGA进行usb控制很有帮助！...

本文研究的IIC总线控制器具有如下特征 1.兼容飞利浦I2C标准，以主机模式与外围设备进行数据通信，对IIC从机模型进行读/读，读/写，写/写，写/读[18]。 2.多主操作 3.软件可编程时钟频率 4.时钟拉伸和等待状态生成 5.软件可编程确认位 6.时钟同步设计 7.仲裁中断丢失，自动转移取消 8.开始/停止/重复启动检测/确认生成 9.总线忙检测(The IIC bus controller studied in this paper has the following characteristics. 1. Compatible with Philips I2C standard, data communication between host mode and peripheral devices, read/read, read/write, write/write, write/read for IIC slave model [18]. 2. Multiple Main Operations 3. Software programmable clock frequency 4. Clock stretching and waiting state generation 5. Software Programmable Confirmation Bit 6. Clock Synchronization Design 7. Loss of arbitration interruption and cancellation of automatic transfer 8. Start/Stop/Repeat Start Detection/Verification Generation 9. Bus busy detection)

this a example for the LCD for altera FPGA cyclone ii EP2C8. implemented in verilog. tested using altera EP2C8 fpga

特大好消息，这是LED全彩控制卡的FPGA的源程序，做LED开发的，绝对有很好的价值(Big good news, this is full-color LED control card FPGA of the source, do LED development, the absolute value of good)

说明：  在Xilinx环境下编写的vhdl程序，实现推箱子的游戏任务，界面很漂亮。(Xilinx environment in the preparation of the VHDL program, realized the game viewing tasks, the interface is very beautiful.)

这是一个利用xilinx的macroblaze将用户程序由flash读取至ddr内存的例程，关键是bootloader的写法。-This is a use of Xilinx macroblaze the user program will read from flash memory to ddr routine, the key is the wording of bootloader.

减1计数器 一、设计要求 用Verilog HDL语言设计一个计数器。 要求计数器具有异步置位/复位功能，可以进行自增和自减计数，其计数周期为2^N（N为二进制位数）。 二、设计原理 输入/输出说明： d：异步置数数据输入； q：当前计数器数据输出； clock：时钟脉冲； count_en：计数器计数使能控制（1：计数/0：停止计数）； updown：计数器进行自加/自减运算控制（1：自加/0：自减）； load_d-a counter a reduction, design requirements using Verilog HDL design of a counter. Asynchronous requests with counter-home/reset functions can be carried out by self and self-count reduction, cycle counting of 2 ^ N (N for binary digit). Second, the principle of design input/output Description : d : asynchronous home several data input; Q : The current counter data output; Clock : clock pulse; Count_en : Counting enable control (1 : Counting/0 : Stop counting); Updown : dollars several self-Canada/reduction Operational control (1 : Since the plus/0 : Since decrease); load_d

这本书介绍了数字应用的底层电路设计的理论及实验程序，非常有用，是一本很好的工具书。(This book describes the application of the underlying digital circuit design theory and experimental procedures, very useful, is a good tool.)

该代码实现了FPGA对USB芯片68013的读写，语言是VERLOD，试验通过。(The code to achieve the FPGA read and write 68013 on the USB chip, the language is VERLOD, through the test. )

四间隔频率变化，并循环输出50~51ms之间的频率。(Four-interval frequency changes and the cycle between 50 ~ 51ms output frequency.)

步进电机控制程序，用vhdl实现。可实现电机的正反转控制-Stepper motor control program, using vhdl implementation. Positive inversion of motor control can be realized