SRAM-based FPGAs are non-volatile devices. Upon powerup, They are required to be programmed from an external source. This procedure allows anyone to easily monitor the bit-stream, and clone the device. The problem then becomes how can you effectively protect your intellectual property from others in an architecture where the part is externally programmed?
上传时间: 2013-11-05
上传用户:wl9454
The NCV7356 is a physical layer device for a single wire data linkcapable of operating with various Carrier Sense Multiple Accesswith Collision Resolution (CSMA/CR) protocols such as the BoschController Area Network (CAN) version 2.0. This serial data linknetwork is intended for use in applications where high data rate is notrequired and a lower data rate can achieve cost reductions in both thephysical media components and in the microprocessor and/ordedicated logic devices which use the network.The network shall be able to operate in either the normal data ratemode or a high-speed data download mode for assembly line andservice data transfer operations. The high-speed mode is onlyintended to be operational when the bus is attached to an off-boardservice node. This node shall provide temporary bus electrical loadswhich facilitate higher speed operation. Such temporary loads shouldbe removed when not performing download operations.The bit rate for normal communications is typically 33 kbit/s, forhigh-speed transmissions like described above a typical bit rate of83 kbit/s is recommended. The NCV7356 features undervoltagelockout, timeout for faulty blocked input signals, output blankingtime in case of bus ringing and a very low sleep mode current.
上传时间: 2013-10-24
上传用户:s蓝莓汁
Single-Ended and Differential S-Parameters Differential circuits have been important incommunication systems for many years. In the past,differential communication circuits operated at lowfrequencies, where they could be designed andanalyzed using lumped-element models andtechniques. With the frequency of operationincreasing beyond 1GHz, and above 1Gbps fordigital communications, this lumped-elementapproach is no longer valid, because the physicalsize of the circuit approaches the size of awavelength.Distributed models and analysis techniques are nowused instead of lumped-element techniques.Scattering parameters, or S-parameters, have beendeveloped for this purpose [1]. These S-parametersare defined for single-ended networks. S-parameterscan be used to describe differential networks, but astrict definition was not developed until Bockelmanand others addressed this issue [2]. Bockelman’swork also included a study on how to adapt single-ended S-parameters for use with differential circuits[2]. This adaptation, called “mixed-mode S-parameters,” addresses differential and common-mode operation, as well as the conversion betweenthe two modes of operation.This application note will explain the use of single-ended and mixed-mode S-parameters, and the basicconcepts of microwave measurement calibration.
上传时间: 2014-03-25
上传用户:yyyyyyyyyy
Multioutput monolithic regulators are easy to use and fi tinto spaces where multichip solutions cannot. Nevertheless,the popularity of multioutput regulators is temperedby a lack of options for input voltages above 30V andsupport of high output currents. The LT3692A fi lls thisgap with a dual monolithic regulator that operates frominputs up to 36V. It also includes a number of channeloptimization features that allow the LT3692A’s per-channelperformance to rival that of multichip solutions.
上传时间: 2014-01-03
上传用户:Huge_Brother
if exists (select * from dbo.sysobjects where id = object_id(N'[dbo].[FK_药品库存_药品资料]') and OBJECTPROPERTY(id, N'IsForeignKey') = 1) ALTER TABLE [dbo].[药品库存] DROP CONSTRAINT FK_药品库存_药品资料 GO if exists (select * from dbo.sysobjects where id = object_id(N'[dbo].[FK_门诊划价明细_门诊划价]') and OBJECTPROPERTY(id, N'IsForeignKey') = 1) ALTER TABLE [dbo].[门诊划价明细] DROP CONSTRAINT FK_门诊划价明细_门诊划价 GO if exists (select * from dbo.sysobjects where id = object_id(N'[dbo].[FK_门诊挂号_门诊挂号类型]') and OBJECTPROPERTY(id, N'IsForeignKey') = 1) ALTER TABLE [dbo].[门诊挂号] DROP CONSTRAINT FK_门诊挂号_门诊挂号类型 GO if exists (select * from dbo.sysobjects where id = object_id(N'[dbo].[产地]') and OBJECTPROPERTY(id, N'IsUserTable') = 1) drop table [dbo].[产地] GO if exists (select * from dbo.sysobjects where id = object_id(N'[dbo].[医生资料]') and OBJECTPROPERTY(id, N'IsUserTable') = 1) drop table [dbo].[医生资料]
上传时间: 2013-11-12
上传用户:sunshie
if exists (select * from dbo.sysobjects where id = object_id(N\'[dbo].[FK_帐单明细_入住单]\') and OBJECTPROPERTY(id, N\'IsForeignKey\') = 1) ALTER TABLE [dbo].[帐单明细] DROP CONSTRAINT FK_帐单明细_入住单 GO if exists (select * from dbo.sysobjects where id = object_id(N\'[dbo].[FK_入住单_客房信息]\') and OBJECTPROPERTY(id, N\'IsForeignKey\') = 1) ALTER TABLE [dbo].[入住单] DROP CONSTRAINT FK_入住单_客房信息 GO if exists (select * from dbo.sysobjects where id = object_id(N\'[dbo].[FK_客房信息_客房类型]\') and OBJECTPROPERTY(id, N\'IsForeignKey\') = 1) ALTER TABLE [dbo].[客房信息] DROP CONSTRAINT FK_客房信息_客房类型
上传时间: 2014-03-23
上传用户:chenhr
c#数据库开发实例:有很多的实例,对学习非常的有意义! 酒店管理系统源代码 医院信息管理系统源代码 图书馆管理系统源代码 财务管理系统源代码 生产管理系统源代码 人力资源管理实例程序源代码 进销存管理实例程序源代码 if exists (select * from dbo.sysobjects where id = object_id(N'[dbo].[采购订单_供货商_fk]') and OBJECTPROPERTY(id, N'IsForeignKey') = 1) ALTER TABLE [dbo].[采购订单] DROP CONSTRAINT 采购订单_供货商_fk GO if exists (select * from dbo.sysobjects where id = object_id(N'[dbo].[采购订单历史_供货商_fk]') and OBJECTPROPERTY(id, N'IsForeignKey') = 1) ALTER TABLE [dbo].[采购订单历史] DROP CONSTRAINT 采购订单历史_供货商_fk
上传时间: 2013-10-29
上传用户:392210346
if exists (select * from dbo.sysobjects where id = object_id(N'[dbo].[采购订单_供货商_fk]') and OBJECTPROPERTY(id, N'IsForeignKey') = 1) ALTER TABLE [dbo].[采购订单] DROP CONSTRAINT 采购订单_供货商_fk GO if exists (select * from dbo.sysobjects where id = object_id(N'[dbo].[采购订单历史_供货商_fk]') and OBJECTPROPERTY(id, N'IsForeignKey') = 1) ALTER TABLE [dbo].[采购订单历史] DROP CONSTRAINT 采购订单历史_供货商_fk GO if exists (select * from dbo.sysobjects where id = object_id(N'[dbo].[采购合同_供货商_fk]') and OBJECTPROPERTY(id, N'IsForeignKey') = 1) ALTER TABLE [dbo].[采购合同] DROP CONSTRAINT 采购合同_供货商_fk GO if exists (select * from dbo.sysobjects where id = object_id(N'[dbo].[进货单_供货商_fk]') and OBJECTPROPERTY(id, N'IsForeignKey') = 1) ALTER TABLE [dbo].[进货单] DROP CONSTRAINT 进货单_供货商_fk
上传时间: 2013-11-15
上传用户:wkxiian
if exists (select * from dbo.sysobjects where id = object_id(N'[dbo].[FK_工资发放历史表_职员基本信息表]') and OBJECTPROPERTY(id, N'IsForeignKey') = 1) ALTER TABLE [dbo].[工资发放历史表] DROP CONSTRAINT FK_工资发放历史表_职员基本信息表 GO if exists (select * from dbo.sysobjects where id = object_id(N'[dbo].[FK_月工资统计表_职员基本信息表]') and OBJECTPROPERTY(id, N'IsForeignKey') = 1) ALTER TABLE [dbo].[月工资统计表] DROP CONSTRAINT FK_月工资统计表_职员基本信息表 GO if exists (select * from dbo.sysobjects where id = object_id(N'[dbo].[FK_职员惩罚表_职员基本信息表]') and OBJECTPROPERTY(id, N'IsForeignKey') = 1) ALTER TABLE [dbo].[职员惩罚表] DROP CONSTRAINT FK_职员惩罚表_职员基本信息表
上传时间: 2014-11-16
上传用户:xinzhch
if exists (select * from dbo.sysobjects where id = object_id(N'[dbo].[mrp物料需求计算_物料编号_fk]') and OBJECTPROPERTY(id, N'IsForeignKey') = 1) ALTER TABLE [dbo].[mrp物料需求计算] DROP CONSTRAINT mrp物料需求计算_物料编号_fk GO if exists (select * from dbo.sysobjects where id = object_id(N'[dbo].[mrp物料需求计算结果_物料编号_fk]') and OBJECTPROPERTY(id, N'IsForeignKey') = 1) ALTER TABLE [dbo].[mrp物料需求计算结果] DROP CONSTRAINT mrp物料需求计算结果_物料编号_fk GO if exists (select * from dbo.sysobjects where id = object_id(N'[dbo].[mrp物料需求历史_物料编号_fk]') and OBJECTPROPERTY(id, N'IsForeignKey') = 1) ALTER TABLE [dbo].[mrp物料需求历史] DROP CONSTRAINT mrp物料需求历史_物料编号_fk GO if exists (select * from dbo.sysobjects where id = object_id(N'[dbo].[物料清单_物料编号_fk]') and OBJECTPROPERTY(id, N'IsForeignKey') = 1) ALTER TABLE [dbo].[物料清单] DROP CONSTRAINT 物料清单_物料编号_fk
上传时间: 2013-11-22
上传用户:wcl168881111111