M25P80 serial memory for applications Verilog program

verilog代码实现的数字密码锁。通过4个并行的10位移位寄存器，分别记录在时钟上升沿时A,B,C,D的输入情况，比如某上升沿输入A，相应时刻A对应的移位寄存器输入1，其他三个移位寄存器输入都为0.另外4个并行的10位寄存器记录密码。这样，密码锁不仅可以识别字符数量，还可以判断出字符的输入次序。(verilog code of digital lock. By four parallel 10-bit shift register, respectively, recorded in the clock rising edge A, B, C, D of inputs, such as a rising edge of input A, the corresponding moments A 1 corresponding to the input shift register, the other three shift bit register inputs are 0. another four parallel 10-bit registers record the password. This lock can not only identify the number of characters, you can also determine the character of the input sequence.)

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)

此代码实现4人表决功能，4人中有三人同意即为通过。(Four voting)

实现输入一正弦波和噪声的叠加，介绍详细欢迎下载(The input of a superposition of sine wave and noise introduced in detail)

能够成功的实现走马灯功能，使LED循环亮灭(To succeed the implementation of the version function, make the LED circular light out)

使用VHDL实现锁相环,是个学习VHDL的好例子,与众分享-PLL using VHDL, VHDL is learning a good example, sharing with the public

说明：  数字钟通过verilog实现，并且支持Modelsim仿真(The digital clock is implemented by Verilog and supports Modelsim simulation)

Quartus2环境下基于VHDL状态机的交通灯程序(VHDL state machine traffic lights based on Quartus2 environment)

挂靠在AMBA2.0的AHB总线上的DMA装置，用于直接发起数据传输。(Anchored the DMA devices the AHB bus AMBA2.0, for initiating data transfer.)

具有先进后出的堆栈功能。此LIFO堆栈具有两个按键（write， read），按下write键后，开始输入数据data0-data3；按下read键后，7段数码管开始倒序显示data3-data0（十进制）。 高级要求（可选）： 按下write键，VGA显示“Write”字样，并同时显示输入数据；按下read键，VGA显示“Read”字样，并同时显示输出数据。