FSM 分两大类:米里型和摩尔型。 组成要素有输入(包括复位),状态(包括当前状态的操作),状态转移条件,状态的输出条件。 设计FSM 的方法和技巧多种多样,但是总结起来有两大类:第一种,将状态转移和状态的操作和判断等写到一个模块(process、block)中。另一种是将状态转移单独写成一个模块,将状态的操作和判断等写到另一个模块中(在Verilog 代码中,相当于使用两个“always” block)。其中较好的方式是后者。其原因 如下: 首先FSM 和其他设计一样,最好使用同步时序方式设计,好处不再累述。而状态机实现后,状态转移是用寄存器实现的,是同步时序部分。状态的转移条件的判断是通过组合逻辑判断实现的,之所以第二种比第一种编码方式合理,就在于第二种编码将同步时序和组合逻辑分别放到不同的程序块(process,block) 中实现。这样做的好处不仅仅是便于阅读、理解、维护,更重要的是利于综合器优化代码,利于用户添加合适的时序约束条件,利于布局布线器实现设计。显式的 FSM 描述方法可以描述任意的FSM(参考Verilog 第四版)P181 有限状态机的说明。两个 always 模块。其中一个是时序模块,一个为组合逻辑。时序模块设计与书上完全一致,表示状态转移,可分为同步与异步复位。
标签: 状态
上传时间: 2015-01-02
上传用户:aa17807091
Abstract: The reality of modern, small form-factor ceramic capacitors is a good reminder to always readthe data sheet. This tutorial explains how ceramic capacitor type designations, such as X7R and Y5V,imply nothing about voltage coefficients. Engineers must check the data to know, really know, how aspecific capacitor will perform under voltage.
上传时间: 2013-11-04
上传用户:梧桐
先进的窗口管理器。可以在你的桌面上实现冻结、解冻、更名、设置总在最上面、设置不总在最上面、闪烁、最大化、最小化、聚焦、隐藏、显示和中断一个可视或不可视窗口的功能。 An advanced window manager that allows you to freeze, dfreeze, rename, set always on top, set not always on top, flash, maximize, minimize, focus, hide, show or terminate an visible or invisible window on your desktop.
上传时间: 2015-03-25
上传用户:qq21508895
The code assumes a two-dimensional computational domain with TMz polarization (i.e., non-zero field Ez, Hx, and Hy). The program is currently written so that the incident field always strikes the lower-left corner of the total-field region first. (If you want a different corner, that should be a fairly simple tweak to the code, but for now you ll have to make that tweak yourself.) I have attempted to provide copious comments in the code and hope that a knowledgeable C programmer can quickly map the approach as described in the paper to what is in the program.
标签: two-dimensional computational polarization non-zero
上传时间: 2013-12-13
上传用户:cylnpy
The tar file contains the following files: ptfsf.c: heart of the perfect TFSF code ptfsf.h: header file for same ptfsf-demo.c: FDTD code which demonstrates use of perfect TFSF code. Essentially this program used to generate results shown in the paper ptfsf-file-maker.c: code to generate an incident-field file using the "perfect" incident fields ptfsf-demo-file.c: FDTD code which uses the perfect incident fields stored in a file fdtdgen.h: defines macros used in much of my code Makefile: simple make-file to compile programs Also include are some simple script files to run the programs with reasonable values. The code assumes a two-dimensional computational domain with TMz polarization (i.e., non-zero field Ez, Hx, and Hy). The program is currently written so that the incident field always strikes the lower-left corner of the total-field region first. (If you want a different corner, that should be a fairly simple tweak to the code, but for now you ll have to make that tweak yourself.)
标签: ptfsf following the contains
上传时间: 2013-11-28
上传用户:风之骄子
Securing Apache 2: Step-by-Step When choosing a web server, Apache very often wins against its competitors because of stability, performance, that fact that it s open source, and many other advantages. But when deciding on which version of Apache to use, the choice is not always so simple. On the one hand there is a very popular, stable version used by millions of users, version 1.3, and on the other hand, there is an enhanced and re-designed version 2.0.
标签: Apache Step-by-Step Securing choosing
上传时间: 2015-09-06
上传用户:gundamwzc
基于Verilog-HDL的硬件电路的实现 9.6 脉冲高电平和低电平持续时间的测量与显示 9.6.1 脉冲高电平和低电平持续时间测量的工作原理 9.6.2 高低电平持续时间测量模块的设计与实现 9.6.3 改进型高低电平持续时间测量模块的设计与实现 9.6.4 begin声明语句的使用方法 9.6.5 initial语句和always语句的使用方法 9.6.6 时标信号发生模块的设计与实现 9.6.7 脉冲高低电平持续时间测量的Verilog-HDL描述 9.6.8 脉冲高低电平持续时间测量的硬件实现
标签: Verilog-HDL 低电平 9.6 时间测量
上传时间: 2013-11-30
上传用户:chenlong
Welcome to the ASTA 3 Help Tutorials. These are documented tutorials that included new user jump start, to file sends to server techniques with non-database servers showing how to use Providers and ServerMethods. A Current version of these tutorials can always be found on line
标签: documented Tutorials tutorials included
上传时间: 2013-12-18
上传用户:gyq
用php开发的crm系统, 推荐使用php4 + MYSQL 4搭建!! 采用Sugar Suite v4.0.1为核心! For a list of new features and other important information about Sugar Suite 4.0.1, please see the ReleaseNotes.doc file. Our goal continues to be to build the customer relationship management system that you have always wanted, so your input is vital. To share ideas with the Sugar Community, ask questions, find answers and submit feedback, please visit our Sugar Forums at http://forums.sugarcrm.com.
上传时间: 2013-12-31
上传用户:z1191176801
windows开源代码 Microsoft Windows is a complex operating system. It offers so many features and does so much that it s impossible for any one person to fully understand the entire system. This complexity also makes it difficult for someone to decide where to start concentrating the learning effort. Well, I always like to start at the lowest level by gaining a solid
标签: Microsoft operating features windows
上传时间: 2015-11-24
上传用户:zhuyibin