build synthesizer on a de2 dev fpga board

用于FPGA的学习，大家值得借鉴，可以好好学习一下(this is for fpga and you can use this.)

vhdl例程代码大全，包含流水灯，数码管，AD,DA转换等(Guinness vhdl code routines, including water lights, digital, AD, DA conversion)

说明：  FPGA按键延时模块，产生key_value和key_flag 可直接例化调用(The key delay module of FPGA)

FPGA控制m25p16flash芯片读写控制spi协议 可实现擦除写入读出功能(SPI protocol for read and write control of m25p16 flash chip controlled by FPGA Erase Write-Read Function)

code for booths multiplier

基于EPM1270的EProm at24c02 驱动-Based on the EPM1270

用vhdl实现的booth算法乘法器，包含了multiplexer和rca adder，同时提供了一个测试文件，modelsim测试通过(Algorithm with a booth multiplier vhdl implementation, including a multiplexer and rca adder, while providing a test file, modelsim test pass)

AMBA总线规范，能对从事嵌入式的同行们有一些帮助，让大家更好的理解ARM 结构和AMBA 体系(AMBA Specification)

说明：  Verilog数字系统设计教程(第二版) 夏宇闻(Verilog Digital System Design Course (2nd Edition) Xia Yuwen)

verilog编写的16阶升余弦滤波器 采用直接型结构实现 对方波进行滤波 输出波形 含testbench文件(order raised cosine filter verilog written 16 direct-type structure to achieve the other wave filtering the output waveform containing testbench file)