Most designers wish to utilize as much of a device as possible in order to enhance the overallproduct performance, or extend a feature set. As a design grows, inevitably it will exceed thearchitectural limitations of the device. Exactly why a design does not fit can sometimes bedifficult to determine. Programmable logic devices can be configured in almost an infinitenumber of ways. The same design may fit when you use certain implementation switches, andfail to fit when using other switches. This application note attempts to clarify the CPLD softwareimplementation (CPLDFit) options, as well as discuss implementation tips in CoolRunnerTM-IIdesigns in order to maximize CPLD utilization.
上传时间： 2014-01-11
上传用户：a471778
Xilinx is disclosing this user guide, manual, release note, and/or specification (the "Documentation") to you solely for use in the developmentof designs to operate with Xilinx hardware devices. You may not reproduce, distribute, republish, download, display, post, or transmit theDocumentation in any form or by any means including, but not limited to, electronic, mechanical, photocopying, recording, or otherwise,without the prior written consent of Xilinx. Xilinx expressly disclaims any liability arising out of your use of the Documentation. Xilinx reservesthe right, at its sole discretion, to change the Documentation without notice at any time. Xilinx assumes no obligation to correct any errorscontained in the Documentation, or to advise you of any corrections or updates. Xilinx expressly disclaims any liability in connection withtechnical support or assistance that may be provided to you in connection with the Information.
上传时间： 2013-11-11
上传用户：zwei41
Xilinx FPGAs require at least two power supplies: VCCINTfor core circuitry and VCCO for I/O interface. For the latestXilinx FPGAs, including Virtex-II Pro, Virtex-II and Spartan-3, a third auxiliary supply, VCCAUX may be needed. Inmost cases, VCCAUX can share a power supply with VCCO.The core voltages, VCCINT, for most Xilinx FPGAs, rangefrom 1.2V to 2.5V. Some mature products have 3V, 3.3Vor 5V core voltages. Table 1 shows the core voltagerequirement for most of the FPGA device families. TypicalI/O voltages (VCCO) vary from 1.2V to 3.3V. The auxiliaryvoltage VCCAUX is 2.5V for Virtex-II Pro and Spartan-3, andis 3.3V for Virtex-II.
上传时间： 2013-10-22
上传用户：aeiouetla
Finite state machines are widely used in digital circuit designs. Generally, when designing a state machine using an HDL, the synthesis tools will optimize away all states that cannot be reached and generate a highly optimized circuit. Sometimes, however, the optimization is not acceptable. For example, if the circuit powers up in an invalid state, or the circuit is in an extreme working environment and a glitch sends it into an undesired state, the circuit may never get back to its normal operating condition.
标签： Creating Machines Mentor State
上传时间： 2013-11-02
上传用户：xauthu
Xilinx is disclosing this user guide, manual, release note, and/or specification (the “Documentation”) to you solely for use in the development of designs to operate with Xilinx hardware devices. You may not reproduce, distribute, republish, download, display, post, or transmit the Documentation in any form or by any means including, but not limited to, electronic, mechanical, photocopying, recording, or otherwise, without the prior written consent of Xilinx. Xilinx expressly disclaims any liability arising out of your use of the Documentation. Xilinx reserves the right, at its sole discretion, to change the Documentation without notice at any time. Xilinx assumes no obligation to correct any errors contained in the Documentation, or to advise you of any corrections or updates. Xilinx expressly disclaims any liability in connection with technical support or assistance that may be provided to you in connection with the Information.
标签： CPLD
上传时间： 2014-12-05
上传用户：qazxsw
Silicon Motion, Inc. has made best efforts to ensure that the information contained in this document is accurate andreliable. However, the information is subject to change without notice. No responsibility is assumed by SiliconMotion, Inc. for the use of this information, nor for infringements of patents or other rights of third parties.Copyright NoticeCopyright 2002, Silicon Motion, Inc. All rights reserved. No part of this publication may be reproduced, photocopied,or transmitted in any form, without the prior written consent of Silicon Motion, Inc. Silicon Motion, Inc. reserves theright to make changes to the product specification without reservation and without notice to our users
标签： GUIDELINES LAYOUT 320 PCB
上传时间： 2013-10-10
上传用户：manga135
This document provides practical, common guidelines for incorporating PCI Express interconnect layouts onto Printed Circuit Boards (PCB) ranging from 4-layer desktop baseboard designs to 10- layer or more server baseboard designs. Guidelines and constraints in this document are intended for use on both baseboard and add-in card PCB designs. This includes interconnects between PCI Express devices located on the same baseboard (chip-to-chip routing) and interconnects between a PCI Express device located “down” on the baseboard and a device located “up” on an add-in card attached through a connector. This document is intended to cover all major components of the physical interconnect including design guidelines for the PCB traces, vias and AC coupling capacitors, as well as add-in card edge-finger and connector considerations. The intent of the guidelines and examples is to help ensure that good high-speed signal design practices are used and that the timing/jitter and loss/attenuation budgets can also be met from end-to-end across the PCI Express interconnect. However, while general physical guidelines and suggestions are given, they may not necessarily guarantee adequate performance of the interconnect for all layouts and implementations. Therefore, designers should consider modeling and simulation of the interconnect in order to ensure compliance to all applicable specifications. The document is composed of two main sections. The first section provides an overview of general topology and interconnect guidelines. The second section concentrates on physical layout constraints where bulleted items at the beginning of a topic highlight important constraints, while the narrative that follows offers additional insight.
上传时间： 2014-01-24
上传用户：s363994250
Automobiles, aircraft, marine vehicles, uninterruptiblepower supplies and telecom hardware represent areasutilizing series connected battery stacks. These stacksof individual cells may contain many units, reaching potentialsof hundreds of volts. In such systems it is oftendesirable to accurately determine each individual cell’svoltage. Obtaining this information in the presence of thehigh “common mode” voltage generated by the batterystack is more diffi cult than might be supposed.
上传时间： 2013-10-24
上传用户：kang1923
Filename: main.c * Description: A simple test program for the CRC implementations. * Notes: To test a different CRC standard, modify crc.h. * * * Copyright (c) 2000 by Michael Barr. This software is placed into * the public domain and may be used for any purpose. However, this * notice must not be changed or removed and no warranty is either * expressed or implied by its publication or distribution.
标签： test implementations Description Filename
上传时间： 2015-02-02
上传用户：leehom61
Java Clock is a FREE Java applet used to display a clock on your Web pages. You can display either analog or digital clock. The full source code of this applet is also available (visit my home page to download it). You may use this applet on your Web pages WITHOUT paying me fee or royalty as long as credit is given (a link to my home page is enough).
标签： display Java applet either
上传时间： 2014-01-12
上传用户：woshiayin
