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MVDR 算法及相关文献 非常详细算法的matlab程序
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- 2020-12-06下载
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cpci express的标准
目前能找到的cpci express总线的标准ContentsIntroduction1.1 Statement of Compliance131.2 Terminology131.3 Applicable Documents181.4 Objectives…191.5 Name and Logo Usage....翻1E,B面201.5.1 Logo Use201.5.2 Trademark polic201.6 Intellectual Property211.7 Special Word Usage221.8 Connectors1.8.1 Legacy CompactPCI Connectors221.8.2 High -Speed Advanced differential Fabric Connectors1.83 UPM Power Connectors∴…251.8.3.1 System Slot/Board and Type 1 Peripheral Slot/Board.251.8.3.2 Switch Slot/ Board261.8.4 eHM C271.8.5 CompactPCI Pluggable Power Supply Connector271.9 Slot and board descriptions281.9.1 Connector Reference Designators...............311.9.2 System Slot and Board1.9.3 Type 1 Peripheral Slot and Board321.9.4 Type 2 Peripheral Slot and Board331.9.5 Hybrid Peripheral slot351.9.6 Legacy Slot1.9.7 Switch Slot and board.36197.13uSwitchSlotandboard.wwwwwww.361.9.7.2 6U Switch Slot and board371.10 EXample Configurations402 Mechanical Requirements452.1 Mechanical Overview452.2 DrayStandard452.3 Units452.4 Keepout Zones452.5 Connector Requirements.452.5.1 ADF Connectors452.5.1.1 Board connectors452.5.1.3 Backplane Connectors with Hot-Plug Suppor o2.5.1.2 Backplane Connectors without Hot-Plug Support46462.5.2 eHM Connectors462.5.2.1 Board Connector Type Designation.462.5.2.2 Backplane Connectors without Hot-Plug Support .........462.5.2.3 Backplane Connectors with Hot-Plug Support..... 462.5.3 UPM Connectors462.5.3.1 Backplane Connectors…………462.5.3.2 Board Connectors without Hot-Plug Support47PICMG EXPO CompactPCI Express Specification, Draft R. 93, March 11, 2005Do Not design To/Do Not claim compliance To/do Not distribute This specification2.5.3.3 Board Connectors with Hot-Plug Support2.5.4 HM Connectors472.5.5 47-Position Pluggable Power Supply Connector472.6 Chassis Subrack Requirements472.7 Backplane Requirements472.7.1 3U Backplane Dimensions and Connector Locations....... 472.7.2 6U Backplane Dimensions and Connector Locations2.8 Slot Numbering and Glyphs512.9 Board Requirements2.9.1 3U System/Type 1/Type 2 Board Dimensions and ConnectorLocations512.9.2 6U System/Type 1/Type 2 Board Dimensions and ConnectorLocations2.9.3 3U Switch board dimensions and connector locations wwm. 5429.4 6U Switch board dimensions and connector locations.552.9.5 Board pcb thickness562.9.6 ESD Discharge Strip562.9.7 ESD Clip562.9.8 Front Panels562.9.9 CompactPcI Express logo572.9.10 PMC/XMC Support….5729.11 Cross sectional vi582.9.12 Component Outline and Warpage582.9.13 Solder Side Cover(Optional)582. 9.14 Component Heights2.9. 15 System Slot Identification592.10 Rear-Panel 1/0 Board Requirements592.10.1 3U Rear-Panel l/o board dimensions592.10.2 6U Rear-Panel l/o board dimensions3 Electrical Requirements623. 1 Signal Definitions623.1.1 PCI Express Signals.623.1.1.1 PCI EXpress Transmit SigInaIs3.1.1.2 PCI Express Receive Signals623.1.1.3 Interconnect Definition633.1.1.3.1 Link definit633.1.1.3.2 Link Grouping.633.1.1.4 Electrical B643. 1.1.4.1 AC Coupling653.1.1.4.2 Insertion loss653.1.1.4.3 Crosstab‖k3.1.1.4,4 Lane-to-Lane skew3.1.1. 4.5 Equalization673.1.1.4.6 Skew within the Differential Pair(Intra-PairSkew)3.1.1.5 Jitter Budget Allocation683.1.1.5.1 Random Jitter(Rj)683.1.1.5.2 System Level Jitter Distribution693.1.1.5.3 Interconnect Jitter Budget693.1.1.5.4 Eye Patterns703. 1.1.5.5 Type 2 Peripheral Transmitter Eye4PICMG EXPO CompactPCI EXpress Specification, Draft R.93, March 11, 2005Do Not Design To/Do Not Claim Compliance To/Do Not Distribute This specification3.1.1.5.6 Controller Transmitter Eye3.1.1.5.7 Type 2 Peripheral Receiver Eye3.1.1.5. 8 Controller Receiver eye743.1.1.5. 9 Backplane Compliance Testing3.1.1.5. 10 Alternative Controller tX measurement.wm.773.1.1.6 Reference Clock783.1.1.6.1Hot-Pug…...….783.1.1.6.2 Clock Fan-Out..793. 1.1.6.3 Clocking dependencies3. 1.1.6.4 AC-Coupling and Biasing793.1.1.6.5 Routing length803. 1.1.6.6 Reference Clock Specification813.1.1.6.7 REFCLK Phase Jitter Specification3.1.2ESD853.1.35VauX.853.1.4 SMBI3.1.4.1 SMBus " Back Powering Considerations883.1.4.2 Backplane Identification and Capability Using SMBus. 883.1.5 PWRBTN# Signal943.1.6 PS ON# Signal.943.1.7 PWR OK Signal.......953.1.8 WAKE# Signal3.1.8. 1 Implementation Note983.1. 9 PERST# Signal993.1.9.1 nitial Power-Up(G3toL0)……………………1003.1.9.2 Power Management States(so to S3/S4 to so)1013.1.9.3 Power down1023.1.10 SYSEN# Signal…1033.1.11 Geographical Addressing1033. 1. 12 LINKCAP Signal1043.1.13/OPin1043.1.14 Reserved pins1043.2 Hot-Plug Support.1043.2.1 Hot-Plug sub-System Architecture1043.2.2 Power enable1073.2.3 Wake#1083.2.4 Module Power good1083.2.5 Present detection1083.2.6 System Management Bus1083.2.7 System Management Bus alert1083.2.8 Attention LED1093.2.9 Attention Switch1093.2.10 DC Specifications1093.3 Backplane Connector Pin Assignments1093.3.1 System SI3.3.1.1 4-Link Configuration1103.3.1.2 2-Link Combination Configuration3.3.2 Peripheral Slot I ype 11133.3. 3 Peripheral Slot Type 2.1153.3.4 Hybrid Peripheral slot.1153.3.5 Legacy slot117PICMG EXPO CompactPCI Express Specification, Draft R. 93, March 11, 2005Do Not design To/Do Not claim compliance To/do Not distribute This specification3.3.6 Switch Slot1173.3.6.1 3U Switch Slot3.3.6.2 6U Switch Slot x4 Link width1183.3.6.3 6U Switch Slot--X8 Link Width.1213.4 Power Supply Requirements…1233.4.1 Current Available1233.4.2 Regulation and Ripple and noise1243.4.3 Backplane Power Decoupling1243. 4.4 Power Supply Timing1243.4.5 Additional Power Requirements for Boards SupportingHot-Ppluc1254 Keying Requirements4Legacy Slots and Legacy boards12642 eHM Ke126A CompactPCI Express Advanced Differential Fabric Connector......129A 1 General data129A 1.1 Objective of this document.129A.1.2Scope129A.1.3 Intended Method of mounting129A 1. 4 Ratings and characteristics130A.1.5 Normative references130A.1.6 Markings……131A 1.7 Type Designation国131A.1.8 Ordering Information132A 1. 9 Special Connector LoadingsA2 Technical InformationA.2.1 Contacts and terminations133A 3 Dimensional Information134A.3.1 Isometric view and common features.134A 3.2 Engagement Information134A.3. 2.1 Electrical Engagement Length134A.3.2.2 First Contact point135A 3.2.3 Perpendicular to Engagement direction135A.3.2.4 Inclination135A 3.3 Backplane Connectors136A 3.3.1 Dimensions1136A.3.3.2 Contacts136A.3.3.3 Contact Tip Geometry…………137A.3.3,4 Terminations137A. 3. 4 Front board connectors wwwwwwwwwww138A,3. 4. Dimensions.138A 3.4.2 Terminations138A 3.5 Mounting Information for Backplane Connectors138A. 3.5. 1 Hole Pattern on Backplanes139A 3.5.2 Backplane Contact Positional Requirements139A.3.5.3 True position of male contacts.139A.3.6 Mounting Information for Front Board Connectors.140A 3.6.1 Hole Pattern on Printed boards140A 4 Characteristics1416PICMG EXPO CompactPCI EXpress Specification, Draft R.93, March 11, 2005Do Not Design To/Do Not Claim Compliance To/Do Not Distribute This specificationA.4.1 Climatic Category141A 4.1.1 Climatic Category Test batch P: Initial EXamination .....141A 4.1.2 Climatic Category Test Batch A: Mechanical Tests.. 141A 4.1.3 Climatic Category Test Batch B: Harsh Environments. 144A.4.1.4 Climatic Category Test Batch C: Damp Heat146A 4.1.5 Climatic Category Test Batch D: ExtendedEnvironmental Tests147A 4.1.6 Climatic Categary Test Batch E: ExtendedEnvironmental Tests148A.4.2 Electrical characteristics148A.4.2.1 Impedance148A 4.2.2 Crosstalk149A.4.2.3 Propagation Delay149A42.4 Differential skew..149A 4.25 Insertion Loss149BEnriched hard-Metric ConnectorB. 1 General data国面国B150B. 1. 1 Objective of this document150B.1.2 Description of the Connector,s Approach150B.1.3 Descriptive Partitions Found Further This document150B 1.4 Normative References15B 1.4.1 Primary references describing the generic Part ofthe co151B.1.42Additionalreferenceswwwwwww.15B.1.5 Intended Method of Mounting151B 1.6 Markings.152B.1.7 Type Designation(General)152B2 Technical Information∴152B 2.1 Definitions152B 2.2 Contacts152B 2.3 Contact Performance Level154B 2.4 Keying154B.2.4.1 Mating rules155B.2.4.2 Examples for mating and nonmating configurations . 156B.2.5 Type Designation156B 2.6 Applicational Information157B 2.6.1 Alignment and Gathering157B26.2 Polarization翻面面∴158B3 Dimensional InformationQB.3.1 General158B.3.2 View and common features158B3.3 Remarks on Mating Properties of eHM Connector…………159B 3. 4 Fixed Board connector160B 3.4.1 Dimensions160B 3.4.2 TerminationsB.3.4.3 Mounting Information for Fixed Board Connectors..161B 3. 4.4 Hole pattern on fixed board161B.3.4 5 Position of connectors on fixed board∴161B 3.5 Free board connectors162B 3.5.1 Dimensions162B 3.5.2 Termination163PICMG EXPO CompactPCI Express Specification, Draft R. 93, March 11, 2005Do Not Design TO/Do Not Claim Compliance To/Do Not Distribute This specificationB.3.5.3 Mounting Information for Free Board Connectors. .......163B 3.5.4 Hole pattern on free board163B 3.5.5 Position of connectors on front board163B4 Characteristics81.163B.4.1 Climatic Category∴163B 4.2 Electrical Characteristics163B.4.2. 1 Creepage and clearance Distances163B 4.2.2 Voltage Proof164B.4.2. 3 Current-Carrying Capacity.164B.4.2.4 Contact resistance.……164B 4.2.5 Insulation Resistance.164B 4.3 Mechanica164B.4.3.1 Mechanical Operation.164B.4.3.2 Engaging and Separating Forces164B 4.3.3 Contact retesert164B 4.3.4 Static Load. Transverse.164B 4.3.5 Gauge Retention Force.164B 4.3.6 Vibration(Sinusoidal.164B 4.3.7 Shock164B 4.3.8 Polarization method165B.4.3.9 Robustness and effectiveness of coding device .........165B.4.3.9.1 Conditions According to IEC60512-7,Test 13e....B165B 5 Test schedule165B.6 Quality Assessment Procedures…………….…..….…......…...165c Universal Power Connector(UPM)166C 1 General data.I....8.4.4面面面..166C.1.1 Objective of this document166C2 Dimensions167C 3 Perpendicular to Engagement Direction169C4 Inclination169C 5 Mounting Information169C 6 Climatic Category.171Figuresg1-1 HM Connectors231-2 Advanced Differential Fabric(ADF) Connector241-3 UPM Power Connector for System and Type 1 Peripheral Slots/Boards..251-4PowerConnectorforswitchslots/boardswwwwww.26-5 eHM Connector1-647- Position CompactS| Pluggable Power Supply Connector……….281-7 CompactPCI Express 3U Slot Examples29-8 Compact PCI Express 6u Slot Examples301-9 System Board311-10 System Slot321-11 Type 1 Peripheral Board321-12 Type 1 Peripheral Slot.331-13 Type 2 Peripheral Board-14 Type 2 Peripheral Slot34PICMG EXPO CompactPCI EXpress Specification, Draft R.93, March 11, 2005Do Not Design To/Do Not Claim Compliance To/Do Not Distribute This specification1-15 Hybrid Peripheral slot351-16 Boards Supported By Hybrid Peripheral Slots361-17 3 Switch Board371-18 3 Switch Slot371-19 6U Switch board38-20 6U Switch Slot391-21 Backplane with Hybrid Peripheral Slots and Legacy Slots401-22 Backplane with all Hybrid Peripheral Slots411-23 Backplane with Type 2 and Hybrid Peripheral Slots421-24 3U Backplane with Switch, System, Type 1, and Type 2 Slots1-256 U Backplane with Switch, System,Type1, and type2S∴………43442-1 Backplane Overall Dimensions482-2 30 Backplane connector Locations492-3 6U Backplane Connector Locations502-4 board compatibility glyphs2-5 Glyph for Boards that Operate in Either System or Peripheral Slots512-6 Slot Compatibility Glyphs……512-7 3U System, Type 1, and Type 2 Board Dimensions and ConnectorLocations522-8 6U System/Type 1/Type 2 Board Dimensions and Connector Locations...532-9 3 Switch board Dimensions and connector locations542-106uswItchboarddimensionsandconnectorlocations..w.wwwwww.552-11 Modification to PCB to Support Thicker Boards562-12 CompactPCI Express Logo572-13 Alternate CompactPC| Express Logo....….….…572-14 Approximate Clearance Between the PMC/XMC PCB and the aDFConnector………………..572-15 Board cross-Sectional view82-16 3U Rear-Panel l/o board dimensions,602-17 6U Rear-Panel l/o Board Dimensions613-1 2-Link and Loss definition643-2 Backplane Connector Footprint683-3 Interconnect jitter allocation703-4 Peripheral TX Eye Mask723-5 Controller TX eye Mask733-6 Peripheral RX Eye Mask743-7 Controller RX Eye Mask753-8 Backplane TX Compliance signal763-9 Backplane RX Eye…763-10 Alternative Controller measurement783-11 Biasing for HCSL Clock Input3-12 Biasing Simulation Results.803-13 Single-Ended Measurement for swing.833-14 Single-Ended Measurement Points for delta cross point833-15 Single-Ended Measurement Points for Rise and Fall Time Matching ..........833-16 Differential Measurement Points for Duty Cycle and Period833-17 Differential measurement points for rise and fall time843-18 Differential Measurement Points for Ringback843-19 Eight-Slot Backplane Example913-20 Power Supply Timing95PICMG EXPO CompactPCI Express Specification, Draft R. 93, March 11, 2005Do Not design To/Do Not claim compliance To/do Not distribute This specification3-21 WAKE Rise and fall time measurement points983-22 WAKE# Circuit Example93-23 Power Up…1013-24 Power Management states1023-25 Power down1033-26 Typical Hot-Plug Interface Implementation1063-27 4-Link Configuration Backplane Example1103-28 2-Link Combination Configuration backplane example112A-1 Sample Part Number with Explanation132A-2 Special Connector Loading 01001面着国面国B面面国33A-3 View of connectors with common features134A-4 Connector Mating Sequence35A-5 Dimensional Drawing of Backplane Connector.136A-6 Contact Geometry for Zone 2 Backplane Connector137A-7 Dimensional Drawing of Front Board Connectors138A-8 Hole Requirements for backplane Connector139A-9 Backplane Pin Contact Positional Tolerance ................................................140A-10 Hole Requirements for the Front Board Connector140B-1 View of Fixed and Free Board Keying Design(Left Perspective, RightDetailed).……155B-2 View of a Mating and a Non-Mating Keying Combination156B-3 View of fixed and free Board connectors..158B-4 View of Fixed Board connector Including polarization Feature.......159B-5 Dimensional drawing of Fixed board eHM connector160B-6 Hole Requirements for eHM on Fixed Board161B-7 Dimensional drawing of eHM Free Board connector…162B-8 Hole Requirements for eHM Free Board Connector............163C-1 UPM-F-7 Female 7-Position power connector dimensional information 167C-2 UPM-F-5 Female 5-Position Power Connector Dimensional Information ....168C-3 Male 7-Position power connector dimensional information168C-4 UPM-M-5 Male 5-Position Power connector dimensional Information169C-5 Hole pattern for 7-Row male uPm Power connector169C-6 Hole pattern for 5-Row male UPM Power connector170C-7 Hole pattern for female 7-Row uPm Power connector..170C-8Holepatternforfemale5-rowuPmpowerconnectorwwww.171Tables3-1 Interconnect Loss Budget Type 1 Peripheral3-2 Interconnect Loss Budget Type 2 Peripheral653-3 Allowable Interconnect Lane-to-Lane skew673-5 Interconnect Jitter buaget on3-4 Total System Jitter Distribution......69703-6 Type 2 Peripheral Transmitter Eye............713-7 Controller TX Compliance Eye Requirements723-8 Type 2 Peripheral RX Compliance Eye Requirements..733-9 Controller RX compliance Eye Requirements743-10 Backplane TX Compliance Signal (Signal Generator)753-11 Backplane RX compliance eye7610PICMG EXPO CompactPCI EXpress Specification, Draft R.93, March 11, 2005Do Not Design To/Do Not Claim Compliance To/Do Not Distribute This specification
- 2020-12-09下载
- 积分：1
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基于Matlab和FPGA的FIR数字滤波器设计及实现
基于FIR数字滤波器的原理和层次化、模块化设计思想，结合Altera公司的CycloneII系列FPGA芯片，提出了FIR数字滤波器的实现硬件方案，给出了采用Matlab、QuartusⅡ设计及实现32阶低通FIR滤波器的方法步骤，仿真及实际测试结果验证了设计方案的正确性，与传统的数字滤波器相比，本文设计的FIR数字滤波器具有更好的实时性、灵活性和实用性。
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常用低速接口verilog代码（Uart/SPI/I2C等）
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- 积分：1
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mqtt物联网数据传输协议
引用github的资源https://mcxiaoke.gitbooks.io/mqtt-cn/Introduction3.2 CONNACK一确认连接请求o3.3 PUBLISH-发布消息o34 PUBACK一发布确认o35 PUBREC-发布收到(QoS2,第一步)°36 PUBREL-发布释放(QoS2,第二步)°3.7P∪ BCOME一发布完成(QoS2,第三步)o3.8 SUBSCR|BE-订阅主题o39S∪BACK-订闶确认o3.10 UNSUBSCR|BE-取消订阅3.11 UNSUBACK-取消订阔确认3.12P| NGREG一心跳请求3.13 PINGRESE一心跳响应o3.14D| SCONNECT一断开连接第四章一操作行为第五章一安全第六章一使用 Websocket第七章一一致性目标附录B-强制性规范声明旧版文档已过期,建议使用 GifTbook版本最新版本:V1.0.12015.10.22文档连接中文版HTMLMQTT3.1.1中文版中文版PDFMQTT3.1.1中文版英文版HTMLMQTT Version 3.1.1英文版PDFMQTT∨ ersion3.1.1许可协议署名-非商业性位用-相同方式共享4.0国际联系方式IntroductionBloghttp://blog.mcxiaoke.comGithub:https://github.com/mcxiaoke.Email:github@mcxiaoke.com开源项目·Rx文档中文翻译:htts:/! github. com/mcxiaoke/ RXDOCS·MQTT协议中文版:htps:/ github. com/ mcxiaoke/mgttAwesome-kotlin:httpsgithub.com/mcxiaokelawesome-kotlin.Kotlin-koi:https:/github.com/mcxiaoke/kotlin-koiNeXt公共组件库:htps!/github.com/xiaoke/Android-Next· PackerNg极速打包:htts;/ github. com/mcxiaoke/ packer- ng-pluginGradle渠道打包https://github.com/mcxiaoke/gradle-packer-plugin·VentuS实现xBus:htps;/github.com/miaoke/BuS磨菇饭App:htps:! github. com/mcxiaoke/minicat·饭否客户端:https:/github.com/mcxiaoke/anfouapp-opensourceVolleyt:https://github.com/mcxiaoke/android-volley第一章-MQTT介绍第一章概逃 Introduction1.1MQTT协议的组织结构 Organization of MQTT本规范分为七个章节:第一章一介绍第二章一MQTT控制报文格式第三章一MQTT控制报文·第四章一操作行为第五章一安全第六章一使用 Websocket第七章一一致性日标附录B一强制性规范声明12术语 Terminology本规范中用到的夭键字必须MUST,不能 MUST NOT,要求 REQUIRED,将会 SHALL,不会 SHALL NOT,应该 SHOULD,不应该 SHOULD NOT,推荐 RECOMMENDED,可以MAY,可选 OPTIONAL都是按照 TE RFC2119[RFC2119]中的描迹解释。网络连接 Network ConnectionMQTT使用的底层传输协议基础设施。客户端使用它连接服务端。它提供有序的丶可靠的丶双向字节流传输。例子见42节应用消息App| ication Message MQT协议通过网络传输应用数据。应用消息通过MQT传输时’它们有关联的服务质量(QoS)和主题( Topic)客户粥C|ient使用MQπT的程序或设备。客户端总是通过网络连接到服务端。它可以发布应用消息给其它相关的客户端。●订阅以请求接受相关的应用消息。·取消订阅以移除接受应用消息的请求从服务端断开连接第一章-MQTT介绍服务端 Server个程序或设备,作为发送消息的客户端和请求订阅的客户端之间的中介σ服务端接受来自客户端的网络连接。接受客户端发布的应用消息。·处理客户端的订阅和取消订阅请求。转发应用消息给符合条件的已订阅客户端订 Subscription订阔包含一个主题过滤器( Topic Filter)和一个最大的服务质量(QoS)等级。订阅与单个会话( Session)关联。会话可以包含多于一个的订阅。会话的每个订阅都有一个不同的主题过主题名 Topic Name附加在应用消息上的一个标签’服务端巳知且与订阔匹配。服务端发送应用消息的一个副本给每一个匹配的容户端订阅。主题过滤器 Topic Filter订阅中包含的一个表达式,用于表示相关的一个或多个主题。主题过滤器可以使用通配符。会话 Session客户端和服务端之间的状态交互。一些会话持续时长与网络连接一样·另一些可以在客户端和服务端的多个连续网络连接间扩展。控制报文 MQTT Contro| Packet通过网络连接发送的信息数据包。MQTT规范定义了十四种不同类型的控制报文,其中一个( PUBLISH报文)用于传输应用消息。1.5数据表示 Data representations1.51二进制位Bits字节中的位从0到7。第7位是最高有效位’第0位是最低有效位。1.52整数数值 Integer data values整数数值是16位’使用大湍序( big-endian,高位字节在低位字节前面)。这意味着一个16位的字在网络上表示为最高有效字节(MSB),后面跟着最低有效字节(LSB)1.53UTF8编码字符串UTF8 encoded strings后面会描逑的控制报文中的文本字段编码为UTF8格式的字符串。UTF8[RFC3629]是一个高效的υ ncode字符编码格式’为了攴持基于文本的通信’它对ASC∏字符的编码做了优化第一章-MQTT介绍每一个字符串都有一个两字节的长度字段作为前缀,它给出这个字符串UTF8编码的字节数,它门在图例1.1UTF8编码字符串的结构中描述。因此可以传送的UTF-8编码的字符串大小有个限制,不能超过65535字节除非另有说明’所有的UTF-8编码字符串的长度都必须在0到65535字节这个范围内。图例1.1UTF8编码字符串的结构 Structure of ute8 encoded strings进制位7-0yte字符串长度的最高有效字节(MsB)byte 2字符串长度的最低有效字节(LSB)byte 3如果长度大于0,这里是UTF-8编码的字符数据。UTF-8编码字符串中的字符数据必须是按照 Unicode规范[ Unicode]定义的和在RFC3629[RFC3629]中重申的有效的UTF8格式。特別需要指出的是,这些数据不能包含字符码在U+D800和U+DFFF之间的数据。如果服务端或客户端收到了一个包含无效UTF-8字符的控制报文”它必须关闭网络连接[MQTT1.53-]。UTF-8编码的字符串不能包含空字符U+0000如果客户端或服务端收到了一个包含U+0000的控制报文’它必须关闭网络连接MQTT-1.53-2]数据中不应该包含下面这些 Unicode代码点的编码。如果一个接收者(服务端或客户端)收到了包含下列任意字符的控制报文,它可以关闭网络连接U+0001和U+00F之间的控制字符∪+007F和∪+009F之问的控制字符Unicode规范定义的非宇符代码点(例如U+ OFFFF)Unicode规范定义的保留字符(例如U+ OFFFF)UTF-8编码序列0XEF0xBB0XBF总是被解释为U+FEFF(零宽度非换行空白字符)’无论它出现在字符串的什么位置’报文接收者都不能跳过或者剥离它[MQTT-153-3]。非规范示例 Non normative example例如,字符串A是一个拉丁字母A后面跟着一个代码点U+2A6D4(它表示一个中日韩统表意文字扩展B中的字符)这个字符串编码如下图例12UTF8编码字符串非规范示例UTF-8 encoded string non normative example第一章-MQTT介绍Bit54byte 1字符串长度MSB(0x0O)00byte 2字符串长度LSB(0×05)byte 3A(0×41)00000bye4(0×F0)000byte 5(OXAA)00byte 6(0×9B)0byte 7(0×94)0001.6编辑约定 Editing conventions本规范用黃色高亮的文本标识一致性声明·毎个一致性声明都分配了一个这种袼式的引用:[MQTT××x-y]项目主页MQTT协议中文版第二章一MQTT控制报文格式第二章MQTT控制报文格式 MQTT ControPacket format目录第一章-个绍第二章一MQTT控制报文格式第三章一MQTT控制报文·第四章一操作行为第五章一安全第六章一使用 Websocket第七章一一致性目标附录B-强制性规范声明2.1MQTT控制报文的结构 Structure of an MQTTControl packetMQπT协议通过交換预定义的MQTT控制报文来通信。这一节描逃这些报文的格式。MQTT控制报文由三部分组成’按照图例2.1-MQ∏控制报文的结构描逃的顺序图例21-MQTT控制报文的结构Fixed header固定报头’所有控制报文都包含Variable header可变报头·部分控制报文包含Payload有效载荷·部分控制报文包含22固定报头 Fixed header每个MQTT控制报文都包含一个固定报头。图例2.2-因定报头的格式描逑了因定报头的格式图例22-固定报头的格式第二章一MQTT控制报文格式Bit65432byte 1MQTT控制报文的类型用于指定控制报文类型的标志位byte 2剩余长度221MQTT控制报文的类型 MQTT Control Packet type位置:第1个字节,二进制位7-4表示为4位无符号值,这些值的定义见表格2.1-控制报文的类型表格2.1-控制报文的类型名字值报文流动方向描述Reserved禁止保留CONNECT客户端到服务端客户端请求连接服务端CONNACK2服务端到客户端连接报文确认PUBLISH两个方向都允许发布消息PUBACK丙个方向都允许QoS1消息发布收到确认PUBREC5两个方向都允许发布收到(保证交付第一步)PUBREL两个方向都允许发布释放(保证交付第二步PUBCOMP7两个方向都允许QoS2消息发布完成(保证交互第三步)SUBSCRIBE8客户端到服务端客户端订阅请求SUBACK9服务端到户风请求摄文确认UNSUBSCRIBE10客户端到服务端客户端取消订阋请求UNSUBACK服务端到客戶端取消订阔报文确认PINGREQ12客户端到服务端跳请求PINGRESP13服务端到客户端心跳响应DISCON№ECT14客户端到服务端客户端断开连接Reserved15禁止保留222标志Fags固定报头第1个字节的剩余的4位[30]包含每个MQTT控制报文类型特定的标志,见表格22-标志位。表格2.2中任何标记为“保留”的标志位·都是保留给以后使用的·必须设置为表柊中出的值[MQT「-22.2-1。如果收到非法的标志’接收者必须关闭网络连接。有美错误处理的详细信息见4.8节MQTT2222]
- 2021-05-06下载
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