1、_SAE Technical Standards Board Rules provide that: “This report is published by SAE to advance the state of technical and engineering sciences. The use of this report is entirely voluntary, and its applicability and suitability for any particular use, including any patent infringement arising theref
2、rom, is the sole responsibility of the user.” SAE reviews each technical report at least every five years at which time it may be revised, reaffirmed, stabilized, or cancelled. SAE invites your written comments and suggestions.Copyright 2013 SAE International All rights reserved. No part of this pub
3、lication may be reproduced, stored in a retrieval system or transmitted, in any form or by any means, electronic, mechanical, photocopying, recording, or otherwise, without the prior written permission of SAE. TO PLACE A DOCUMENT ORDER: Tel: 877-606-7323 (inside USA and Canada) Tel: +1 724-776-4970
4、(outside USA) Fax: 724-776-0790 Email: CustomerServicesae.org SAE WEB ADDRESS: http:/www.sae.orgSAE values your input. To provide feedback on this Technical Report, please visit http:/www.sae.org/technical/standards/AS5643AAEROSPACESTANDARDAS5643 REV. A Issued 2004-12 Revised 2006-10 Reaffirmed 2013
5、-04 Superseding AS5643 IEEE-1394bInterface Requirements for Military and Aerospace Vehicle Applications RATIONALEAS5643A has been reaffirmed to comply with the SAE five-year review policy. TABLE OF CONTENTS 1. SCOPE 31.1 Purpose . 31.2 Application . 31.3 Interpretation . 31.4 Additions to the IEEE-1
6、394, IEEE-1394a, and IEEE-1394b Standards . 31.4.1 Use of Asynchronous Streams . 31.4.2 A Fixed Frame Rate 41.4.3 Synchronization Via Start of Frame Packets 41.4.4 Static Assignment of Channel Numbers . 41.4.5 Pre-Assignment of Bandwidth . 41.4.6 Vertical Parity Check . 41.4.7 Anonymous Subscriber M
7、essaging 42. DEFINITIONS AND APPLICABLE DOCUMENTS . 42.1 Definitions . 42.2 Government Documents . 72.3 Non-Government Documents . 72.4 Applicable References 73. IEEE-1394B REQUIREMENTS 73.1 Data Bus Architecture and Operation . 73.1.1 Basic Network Architecture . 83.1.2 Basic Network Architecture W
8、ith a Loop 93.1.3 Representative Triplex Network Architecture With Loops 103.2 Data Bus Characteristics 113.2.1 Data Format 113.2.2 Bit Ordering . 113.2.3 Transmission Method 123.2.4 IEEE 1394 Packet Formats . 123.2.5 IEEE-1394b Data Bus Initialization and Configuration . 223.3 Node Operation . 243.
9、3.1 CC Node Operation 243.3.2 Remote Node Operation . 333.3.3 Data Packet Types 36Copyright SAE International Provided by IHS under license with SAENot for ResaleNo reproduction or networking permitted without license from IHS-,-,-SAE AS5643A Page 2 of 40 4. INTERFACE DEFINITIONS 384.1 Destination N
10、ode Channel Assignments 38APPENDIX A SLASH SHEET GUIDANCE . 40FIGURE 1 BASIC NETWORK WITH SINGLE CC COLORS, SHADING, AND OUTLINES COULD INDICATE DIFFERENT TYPES OF NODES ON THE BUSSES . 8FIGURE 2 BASIC NETWORK WITH SINGLE CC AND A LOOP COLORS, SHADING, AND OUTLINES COULD INDICATE DIFFERENT TYPES OF
11、NODES ON THE BUSSES . 9FIGURE 3 REPRESENTATIVE TRIPLEX CC ARCHITECTURE 10FIGURE 4 BIT ORDERING 11FIGURE 5 ASYNCHRONOUS STREAM PACKET 13FIGURE 6 ASM HEADER 13FIGURE 7 PAYLOAD DATA AREA 15FIGURE 8 PACKET TRAILER 18FIGURE 9 ASYNCHRONOUS TRANSACTION PACKET . 20FIGURE 10 ACKNOWLEDGE PACKET 22FIGURE 11 IN
12、ITIALIZATION AND CONFIGURATION TIMING 24FIGURE 12 STOF PACKET . 25FIGURE 13 TEST MODE COMMAND WORD . 29FIGURE 14 TEST MODE READ COMMAND 30FIGURE 15 TEST MODE WRITE COMMAND 31FIGURE 16 NORMAL BUS OPERATION 34FIGURE 17 FLOWCHART OF SYSTEM INTEGRITY MANAGEMENT 36FIGURE 18 ALLOCATING RESERVED BANDWIDTHS
13、 AND STOF TRANSMIT OFFSETS WITH MIXED DATA . 37TABLE 1 SUPPORTED DATA TYPES 11TABLE 2 SPEED BITS . 17TABLE 3 AN EXAMPLE OF REMOTE NODE CHANNEL ASSIGNMENTS . 38Copyright SAE International Provided by IHS under license with SAENot for ResaleNo reproduction or networking permitted without license from
14、IHS-,-,-SAE AS5643A Page 3 of 40 1. SCOPE This SAE Aerospace Standard (AS) establishes the requirements for the use of IEEE-1394b as a data bus network in military and aerospace vehicles. It defines the concept of operations and information flow on the network. As discussed in 1.4, this specificatio
15、n contains extensions/restrictions to “off-the-shelf” IEEE-1394 standards, and assumes that the reader already has a working knowledge of IEEE-1394. This document is referred to as the “base” specification, containing the generic requirements that specify data bus characteristics, data formats and n
16、ode operation. It is important to note that this specification is not stand-alone - severalrequirements provide only example implementations and delegate the actual implementation to be specified by the network architect/integrator for a particular vehicle application. This information is typically
17、contained in a “network profile” slash sheet that is subservient to this base specification. In a similar manner, the electrical characteristics of thebus media, as well as connector information is contained in a “physical layer” slash sheet, that also may be unique to a particular vehicle applicati
18、on. In summary, full understanding of this specification requires knowledge of IEEE-1394b standards and access to the physical layer slash sheets and the slash sheets and handbook for the target application. 1.1 Purpose The purpose of this document is to standardize an approach to using IEEE-1394 in
19、 safety-critical/mission-critical applications for military and aerospace vehicles. The information herein will be used to assist the design, fabrication, and maintenance of the nodes that interface via the vehicles network. This document is controlled and maintained by the SAE with technical suppor
20、t from Remote Node vendors. 1.2 Application The IEEE-1394 Network defined in this document provides a deterministic, rate based communication protocol overlaid on the existing IEEE-1394 standard capabilities. 1.3 Interpretation The following interpretations shall be placed upon these words, unless s
21、tated otherwise, where they are used in this document.May: An allowed action. Shall: A mandatory requirement. Should: A recommended action. Will: A declaration of intent. 1.4 Additions to the IEEE-1394, IEEE-1394a, and IEEE-1394b Standards Additions include the use of asynchronous stream packets, a
22、fixed frame rate synchronized with a Start Of Frame packet, addition of a Vertical Parity Check, static assignment of channel numbers, pre-assignment of bandwidth, and use of Anonymous Subscriber Messaging. 1.4.1 Use of Asynchronous Streams Asynchronous streams are used for most communication on the
23、 network. Asynchronous and isochronous packets are not required but may be utilized. Architectures and protocols discussed in the context of this document are based on asynchronous streams, unless it is otherwise mentioned. An example of using asynchronous packets would be to allow test equipment to
24、 read data from a Configuration ROM. An example of using isochronous packets would be for streaming video and/or audio. Copyright SAE International Provided by IHS under license with SAENot for ResaleNo reproduction or networking permitted without license from IHS-,-,-SAE AS5643A Page 4 of 40 1.4.2
25、A Fixed Frame Rate If isochronous packets are not utilized, there is no requirement for Cycle Start packets to be sent at the normal 125-microsecond rate. Instead, this implementation provides a fixed frame rate for synchronization of the network. If isochronous packets are utilized, it is necessary
26、 to utilize the Cycle Master function so the 125-microsecond periodic cycle starts are available to isochronous sources that expect them. Figure 18 in 3.3.3.3 shows an example of interleaving isochronous packets and asynchronous stream packets. 1.4.3 Synchronization Via Start of Frame Packets A Star
27、t Of Frame (STOF) packet is transmitted by the Control Computer on each bus at a periodic (e.g. 100 Hertz) frame rate. This packet informs all nodes on the bus that a new frame has started. 1.4.4 Static Assignment of Channel Numbers Because asynchronous stream packets are, in reality, isochronous pa
28、ckets, the destination of the packet is identified by a channel number. Unlike standard 1394, the channel numbers for destination nodes are not assigned by an Isochronous Resource Manager (IRM). Instead, the channel numbers for each node on the bus are pre-assigned, are application specific, and wil
29、l be defined as required by the architecture. 1.4.5 Pre-Assignment of Bandwidth The lack of an IRM requires that bandwidth be pre-assigned, also. Transmit and receive times for each node on the bus are assigned as offsets, in increments of 1 microsecond, from the start of each frame (STOF packet). T
30、he offsets for each node on the bus are application specific and will be defined as required by the architecture. 1.4.6 Vertical Parity Check Vertical Parity Checking (VPC) is performed on the data area of each packet as an adjunct to the Cyclic Redundancy Check (CRC) performed by the 1394 physical
31、layer devices. The VPC provides additional data integrity as the messages progress through the physical and software layers. 1.4.7 Anonymous Subscriber Messaging Anonymous Subscriber Messaging (ASM) is a protocol, in which, a Remote Node on the network can subscribe to each message that it requires.
32、 The ASM software in the Remote Node will forward only the messages to which the Remote Node has subscribed. ASM is an upper level protocol tailored for the demands of highly modular embedded real time systems operating under a “data push” paradigm. ASM is designed to be independent of lower level p
33、rotocols and, as such, does not utilize the 1394 header to transport ASM-peculiar information. ASM is tailored to support deterministic, secure, low-latency communication between processors, sensors, instrumentation, and displays in mission-critical applications. It uses Message IDs to decouple the
34、network traffic from physical addresses so application software can communicate without knowledge of network topology. 2. DEFINITIONS AND APPLICABLE DOCUMENTS 2.1 Definitions ASM HEADER: Anonymous Subscriber Messaging Header, the header that contains information relevant to the node transmitting the
35、 data and the communication status of that node. ASYNCHRONOUS: (1) pertaining to a transmission technique that does not require a common clock between the communicating devices. Timing signals are derived from special characters in the data stream itself. (2) not synchronous, not occurring or existi
36、ng at the same time or having the same period or phase. Copyright SAE International Provided by IHS under license with SAENot for ResaleNo reproduction or networking permitted without license from IHS-,-,-SAE AS5643A Page 5 of 40 ASYNCHRONOUS STREAM PACKET: An isochronous packet that occurs in the f
37、airness interval or asynchronous time frame. Data transmission is carried out in accordance with asynchronous arbitration rules; however, there is no acknowledge packet or response returned by the targeted node. ASYNCHRONOUS TRANSACTION: A transaction carried out in accordance with asynchronous arbi
38、tration rules. The transaction is always a request/response transaction and provides an acknowledgement of data delivery. BER: Bit Error Rate is a parameter relating to the quality of a serial transmission system. BER is the percentage of bits having errors, relative to the total number of bits rece
39、ived in a transmission. BER is usually expressed as ten to a negative power.BIG ENDIAN: Describes a memory-addressing architecture in which, within a given multi-byte numeric representation, the most significant byte has the lowest address (the word is stored big-end-first). Big-endian byte order is
40、 also sometimes called network order. BRANCH: A node physically connected to two or more nodes (i.e. two or more ports are connected). BUS: One of the 1394 trees connected to each CC Branch. BUS MANAGER: One node residing on the bus may be selected to provide serial bus services for the benefit of t
41、he community of all nodes residing on the bus. CC: Control Computer. The CC is the root node, Cycle Master (if used), and Bus Manager for its respective data bus. CC-BRANCH: One set of redundant resources (e.g. a CC including all of its buses and Remote Node). CHANNEL/CHANNEL NUMBER: The means by wh
42、ich Isochronous and Asynchronous Stream packets are addressed. Data is transmitted onto the bus with a particular channel number. Nodes on the bus wishing to receive the data are configured to accept packets addressed with that channel number.CORBA: Common Object Request Broker Architecture, OMGs op
43、en, vendor-independent architecture and infrastructure that computer applications use to work together over networks. Using the standard protocol IIOP, a CORBA-based program from any vendor, on almost any computer, operating system, programming language, and network, can interoperate with a CORBA-ba
44、sed program from the same or another vendor, on almost any other computer, operating system, programming language, and network. CRC: Cyclic Redundancy Check a check summing algorithm generated and verified by the 1394 hardware. CYCLE MASTER: The node that generates the periodic (125s) cycle start pa
45、cket. DATA PUMP: Internal equipment software parameters or memory values placed on the bus to support integration and test. FRAME: The time interval between consecutive STOF messages (e.g. 10.0 milliseconds). ISOCHRONOUS: Uniform in time (i.e. having equal duration) and recurring at regular interval
46、s. A form of data transmission that guarantees to provide a certain minimum data rate, as required for time-dependent data such as video or audio. Isochronous transmission transmits asynchronous data over a synchronous data link so that individual characters are only separated by a whole number of b
47、it-length intervals. This is in contrast to asynchronous transmission, in which the characters may be separated by arbitrary intervals, and with synchronous transmission. ISOCHRONOUS RESOURCE MANAGER: The node that maintains the channels available, bandwidth available, and bus manager ID registers.
48、ISOCHRONOUS TRANSFER: A data transmission method that occurs uniformly in time and recurs at regular intervals (integer multiple of 125 s). Copyright SAE International Provided by IHS under license with SAENot for ResaleNo reproduction or networking permitted without license from IHS-,-,-SAE AS5643A Page 6 of 40 LEAF: A node physically connected to only one other node (i.e. only one port is connected). LINK LAYER: The serial bus layer that defines the data transfer services. It also provides addressing, data checking, and data framing. LRC: Line Replaceable Component. LRU: Line Replac
