FFT程序，基于verilog

交通灯控制系统VHDL源码，用VHDL语言、MAXPLUS2环境设计实现(VHDL core)

基于vhdl语言的15位gold序列的设计的开端一部分程序(Vhdl language based on sequences of the 15 gold as part of the beginning of the design process)

双端口静态RAM的VHDL程序，具体芯片型号为IDT7005(DUAL-PORT STATIC RAM)

说明：  用verilog HDL编程实现的基于DAC0832的三角波信号，可借鉴编程实现DAC0832芯片控制(Programming with verilog HDL DAC0832-based triangular wave signal, we may learn programming DAC0832 chip control)

本文分析了当前国内外出租车计费系统的基本组成和工作原理及主要的两种设计方式:基于单片机的设计方式和基于FPGA的设计方式；并对这两种实现方式的优点和缺点进行分析，比较后确定本系统的方案：基于FPGA的出租车计费系统的设计。(This paper analyzes the current taxi charging system at home and abroad, working principle and basic components of two major design approach: the design methods based on single chip FPGA-based design approach and the two implementations to analyze the strengths and weaknesses, After comparing the program to determine the system: FPGA-based taxi billing system.)

说明：  Digital pre-distortion (DPD) is an advanced digital signal-processing technique that mitigates the effects of power amplifier (PA) nonlinearity in wireless transmitters. DPD plays a key role in providing efficient radio digital front-end (DFE) solutions for 3G/4G basestations and beyond. Modern FPGAs are a promising target platform for the implementation of flexible wireless DFE solutions, including DPD.

dds 频率可控，32位 输出为12位 已含有.hex文件，直接装载致ROM即可~(dds frequency-controlled, 32-bit output is 12 already contains. hex file can be loaded directly caused ROM ~)

最大值求解是利用System Generator平台实现的比较方便不用自己写verilog代码就可以在Xilinx平台下使用，非常方便实用！

数字秒表的VHDL代码。当设计文件加载到目标器件后，设计的数字秒表从00-00-00开始计秒。，直到按下停止按键（按键开关S2）。数码管停止计秒。按下开始按键（按键开关S1），数码管继续进行计秒。按下复位按键（核心板上复位键）秒表从00-00-00重新开始计秒。(The VHDL code for digital stopwatch. When the design document loaded into the target device, the designed digital stopwatch count the seconds from the 00-00-00. Until you press stop key (key switch S2). Nixie tube stop count seconds. Press the start button (key switch S1), the digital control continue to count seconds. Press the reset button (core panel reset button) to restart the stopwatch count seconds from the 00-00-00.)

时间同步后即可确定每帧数据的起始位置，这样就能完整的截取下每一帧。但是，数据中还带有频偏信息。在常规的通信系统中，多普勒很小仅仅会带来很小的频偏，但是在大多普勒的情况下，频偏将非常大，20马赫的速度将会带来将近34K的频偏。因此，如何很好的纠正频偏即为本系统的难点。 OFDM中，我们将大于子载波间隔倍数的频偏称为整数倍频偏，而将小于一个子载波间隔的频偏称为小数倍频偏。频偏矫正精度只要能保证小于十分之一倍的子载波间隔，频偏就不会对均衡和解调造成影响。本文中我们借鉴这种思想，由于硬件资源限制，我们将在接收端做64点FFT，即相当于将频域划分为64份，我们将小于 的频偏称为小数倍频偏，将 整数倍的频偏称为整数倍频偏。本程序即基于SCHIMDL经典方法完成小数倍频偏纠正(After time synchronization can determine the starting position of each frame data, so you can complete the interception of each frame. However, in the data with frequency information. In conventional communication systems, doppler small will bring only small deviation, but in the case of most of the doppler, frequency PianJiang is very large, 20 Mach speed will lead to deviation of nearly 34 k. Therefore, how to good to correct deviation is the difficulty of this system. OFDM, we will be bigger than the sub-carrier spacing ratio of frequency deviation is called the integer frequency offset, and the interval will be less than a child carrier frequency offset is called decimal frequency doubling. Deviation is less than one over ten times as long as can guarantee accuracy of sub-carrier spacing, deviation will not affect balance and demodulation. This article, we draw lessons from the idea, due to the limited hardware resources, we will do 64 points FFT at the receiving end, which is equ)