1、INCITS Technical ReportInformation Technology SCSI Domain Validation (SDV)INCITS TR-28-2002 Developed by the InterNationalCommittee for InformationTechnology Standards (INCITS)Reaffirmed as INCITS/TR-28-2002 (R2017)INCITS TR-28-2002 (R2007)INCITS Technical ReportSecretariatInformation Technology Ind
2、ustry CouncilAbstractThis technical report describes the methods by which users may measure the performance characteristicsof a parallel SCSI domain. This report does not provide definitions or specifications of components utilizedin configuring the domain. Physical attributes of the domain are defi
3、ned in the SCSI family of standards.These standards should be consulted before implementing the recommendations outlined in this technicalreport. The information in this technical report does not supersede any requirements in the referencedstandards.This Technical Report is one in a series produced
4、by the InterNational Committeefor Information Technology Standards (INCITS). The secretariat for INCITS is heldby the Information Technology Industry Council (ITI), 1250 Eye Street, NW, Suite200, Washington, DC 20005.As a by-product of the standards development process and the resources ofknowledge
5、devoted to it, INCITS from time to time produces Technical Reports.Such Technical Reports are not standards, nor are they intended to be used assuch.INCITS Technical Reports are produced in some cases to disseminate thetechnical and logical concepts reflected in standards already published or underd
6、evelopment. In other cases, they derive from studies in areas where it is foundpremature to develop a standard due to a still changing technology, orinappropriate to develop a rigorous standard due to the existence of a number ofviable options, the choice of which depends on the users particular req
7、uirements.These Technical Reports, thus, provide guidelines, the use of which can result ingreater consistency and coherence of information processing systems.When the draft Technical Report is completed, the Technical Committee approvalprocess is the same as for a draft standard. Processing by INCI
8、TS is also similarto that for a draft standard.CAUTION: The developers of this technical report have requested that holders ofpatents that may be required for the implementation of the technical report,disclose such patents to the publisher. However, neither the developers nor thepublisher have unde
9、rtaken a patent search in order to identify which, if any, patentsmay apply to this technical report.As of the date of publication of this technical report, following calls for theidentification of patents that may be required for the implementation of the technicalreport, notice of one or more clai
10、ms has been received.By publication of this technical report, no position is taken with respect to thevalidity of this claim or of any rights in connection therewith. The known patentholder(s) has (have), however, filed a statement of willingness to grant a licenseunder these rights on reasonable an
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12、 are not required to avoid infringement in the use of this technical report.INCITSTechnicalReportSeriesPublished byAmerican National Standards Institute25 West 43rd Street, New York, New York 10036Copyright 2002 by Information Technology Industry Council (ITI)All rights reservedNo part of this publi
13、cation may be reproduced in anyform, in an electronic retrieval system or otherwise,without prior written permission of the publisher.Printed in the United States of AmericaPATENTSTATEMENTi Table of Contents 1 Scope1 2 References .1 2.1 Approved references .1 2.2 References under development 1 3 Def
14、initions, abbreviations, and keywords .2 3.1 Definitions 2 3.2 Abbreviations .3 3.3 Keywords .4 4 Examples of parallel SCSI domain configurations .5 4.1 SCSI bus segment and driver-receiver connections .5 4.2 Typical configurations6 5 Domain examination.9 5.1 General 9 5.2 Topology discovery9 5.3 As
15、sumptions 9 5.4 Data patterns .9 5.5 Test descriptions9 5.5.1 Test order .9 5.5.2 Test conditions10 5.5.3 Basic test 10 5.5.4 Enhanced test.10 5.5.5 Test output11 5.6 Margin Test11 5.6.1 Assumption .11 5.6.2 Test order .11 5.6.3 Test conditions11 5.6.4 Margin test and parameters12 5.6.5 Test combina
16、tions.13 5.6.6 Test direction 13 5.6.7 Test criteria .13 5.6.8 Test output13 5.6.9 Flow chart .13 Table of Figures Figure 1 Driver-receiver connection 5 Figure 2 Simplified domain A.6 Figure 3 Simplified domain B.6 Figure 4 Example domain with expander 7 Figure 5 Example dual initiator domain .7 Fig
17、ure 6 Example of complex domain .8 Figure 7 Domain examination14 Figure 7 continued Domain validation .15 Figure 7 continued Domain examination.16 INCITS TR-28-2002 (R2007)1 1 Scope This technical report provides guidance to users of parallel SCSI beyond that contained in the formal standards. This
18、technical report describes the methods of characterizing a parallel SCSI domain by varying analog driver parameters and monitoring the results. The architecture for varying receiver parameters may be consistent with that used when varying analog driver parameters. The architecture for varying receiv
19、er parameters is not addressed in this technical report. This technical report addresses measuring the performance of driver-receiver connections. SCSI Parallel Interface-4 specifies minimum requirements of those connections. 2 References The following standards contain provisions that, through refe
20、rence in the text, constitute provisions of this technical report. At the time of publication, the revisions indicated were valid. All standards are subject to revision, and parties to agreements based on this technical report are encouraged to investigate the possibility of applying the most recent
21、 revisions/editions of the standards listed below. Copies of the following standards may be obtained from ANSI: approved ANSI standards, approved and draft international and regional standards (ISO, IEC, CEN/CENELEC, ITUT), and approved and draft foreign standards (including BSI, JIS, and DIN). For
22、further information, contact ANSI Customer Service Department at 212-642-4900 (phone), 212-302-1286 (fax) or via the World Wide Web at http:/www.ansi.org. For further information or copies of NCITS Standards contact: NCITS Secretariat at 202-737-8888 (phone), 202-638-4922 (fax) or via E-mail at ncit
23、sitic.org. To obtain copies of these standards contact: NCITS Online Store, managed by Techstreet, at 1327 Jones Drive, Ann Arbor, MI 48105 at 734-302-7801 (phone), 800-699-9277 (phone), or 734-302-7811 (fax); or Global Engineering at 15 Inverness Way East, Englewood, CO 80112-5704 at 303-792-2181 (
24、phone), 800-854-7179 (phone), or 303-792-2192 (fax). 2.1 Approved references Currently, there are no approved normative references. 2.2 References under development At the time of publication, the following referenced standards were still under development. For information on the current status of t
25、he standard, or regarding availability, contact the relevant standards body or other organization as indicated. T10/1365-D, SCSI Parallel Interface-4 T10/1157-D, SCSI Architecture Model-2 T10/1416-D, SCSI Primary Commands-3 NCITS TR-23:1998, SCSI Enhanced Parallel InterfaceINCITS TR-28-2002 (R2007)2
26、 3 Definitions, abbreviations, and keywords 3.1 Definitions 3.1.1 application client: An object that is the source of SCSI commands. Further definition of an application client is found in the SCSI Architecture Model-2 standard. 3.1.2 asynchronous transfer: An information transfer that uses the asyn
27、chronous REQ/ACK handshake with a REQ/ACK offset of zero. 3.1.3 byte: Indicates an 8-bit construct. 3.1.4 domain: The configuration of components within a service delivery subsystem that includes SCSI expanders, terminators, and cable plants that logically connect all attached SCSI initiators and SC
28、SI targets. 3.1.5 double transition (DT): The latching of data on both the assertion edge and the negation edge of the REQ or ACK signals. 3.1.6 driver: The circuitry used to control the state of the SCSI bus segment. 3.1.7 driver-receiver connection: An assembly of driver, receiver, terminators, an
29、d the cable plant that produce the electrical coupling between the driver and receiver involved in the measurement. 3.1.8 expander: A device that connects SCSI bus segments together to form a single domain. 3.1.9 fast-5: Negotiated to receive synchronous data at a transfer period that translates int
30、o a transfer rate less than or equal to 5 megatransfers per second. 3.1.10 fast-10: Negotiated to receive synchronous data at a transfer period that translates into a transfer rate greater than 5 megatransfers per second and less than or equal to a transfer rate of 10 megatransfers per second. 3.1.1
31、1 fast-20: Negotiated to receive synchronous data at a transfer period that translates into a transfer rate greater than 10 megatransfers per second and less than or equal to a transfer rate of 20 megatransfers per second. 3.1.12 fast-40: Negotiated to receive synchronous data at a transfer period t
32、hat translates into a transfer rate greater than 20 megatransfers per second and less than or equal to a transfer rate of 40 megatransfers per second. 3.1.13 fast-80: Negotiated to receive synchronous data at a transfer period that translates into a transfer rate greater than 40 megatransfers per se
33、cond and less than or equal to a transfer rate of 80 megatransfers per second. 3.1.14 fast-160: Negotiated to receive synchronous data at a transfer period that translates into a transfer rate of 160 megatransfers per second. 3.1.15 initiator: Synonymous with SCSI initiator port (see 3.1.26). 3.1.16
34、 logical unit: An externally addressable entity within a SCSI target device. See the SCSI Architecture Model-2 standard for a detailed definition of a logical unit. 3.1.17 logical unit number (LUN): An identifier for a logical unit. INCITS TR-28-2002 (R2007)3 3.1.18 margining: The process of measuri
35、ng the response of driver-receiver connections to controllable changes in the driver properties. 3.1.19 megatransfers per second: The repetitive rate that data are transferred across the bus. This is equivalent to 220 bytes per second on an 8-bit wide bus. 3.1.20 path: The cable, printed circuit boa
36、rd or other means for providing the conductors and insulators that connect two or more points. 3.1.21 receiver: The circuitry used to detect the state of the SCSI bus segment. 3.1.22 SCSI address: The decimal representation of the unique address assigned to a SCSI device. 3.1.23 SCSI bus segment: A
37、SCSI bus segment consists of all the conductors and connectors required to attain signal line continuity between every driver, receiver, and two terminators for each signal. It is not necessary that a SCSI bus segment contain any specific combination of devices but a segment has at least two devices
38、 attached. Devices include: targets, initiators, and expanders in this context. The end-points of SCSI bus segments are defined by the position of the terminators. 3.1.24 SCSI device: A device containing at least one SCSI port and the means to connect its drivers and receivers to the bus segment. 3.
39、1.25 SCSI ID: The bit-significant representation of the SCSI address where ID0 is the least significant bit. 3.1.26 SCSI initiator port: A SCSI initiator device object acts as the connection between application clients and the service delivery subsystem through which requests and responses are route
40、d. See the SCSI Architecture Model-2 standard for a detailed definition of a SCSI initiator port. 3.1.27 SCSI target port: A SCSI target device object that contains a task router and acts as the connection between device servers and task managers and the service delivery subsystem through which requ
41、ests and responses are routed. See the SCSI Architecture Model-2 standard for a detailed definition of a SCSI target port. 3.1.28 SCSI Terminator: The terminator is at each end of a SCSI bus segment. The terminator provides impedance match and biasing, holding the bus in a negated state when it is n
42、ot driven. 3.1.29 service delivery subsystem: That part of a SCSI I/O system that transmits service requests to a logical unit or target and returns logical unit or target responses to an initiator. 3.1.30 single transition (ST): The latching of data only on the assertion edge of the REQ or ACK sign
43、als. 3.1.31 synchronous transfer: An information transfer that uses an REQ/ACK offset other than zero. 3.1.32 target: Synonymous with SCSI target port (see 3.1.27). 3.2 Abbreviations Async Asynchronous data transfer CRC Cyclic redundancy check DT Double transition ECP Expander communication protocol
44、 (see SCSI Parallel Interface-4) LUN Logical unit number SCSI Small computer system interface ST Single transition T Terminator INCITS TR-28-2002 (R2007)4 3.3 Keywords 3.3.1 may: A keyword that indicates flexibility of choice with no implied preference. 3.3.2 may not: Keywords that indicates flexibi
45、lity of choice with no implied preference. 3.3.3 should: A keyword indicating flexibility of choice with a preferred alternative; equivalent to the phrase “it is recommended.” INCITS TR-28-2002 (R2007)5 4 Examples of parallel SCSI domain configurations 4.1 SCSI bus segment and driver-receiver connec
46、tions A SCSI bus segment consists of all the conductors and connectors required to attain signal line continuity between every driver, receiver, and two terminators for each signal. Examples of SCSI bus segments are shown in Figure 2, Figure 3, Figure 4, Figure 5, and Figure 6. The end-points of SCS
47、I bus segments are defined by the position of the terminators. The driver-receiver connection is an assembly of driver, receiver, terminators, and the cable plant that produce the electrical coupling between the driver and receiver involved in the measurement. Figure 1 details a complementary set of
48、 driver-receiver connections. This technical report considers single driver-receiver connections only. A complete characterization of a SCSI bus segment requires every driver-receiver connection in the SCSI bus segment to be examined. Since SCSI is a bi-directional architecture, a minimum of two dri
49、ver-receiver connections exist in every SCSI bus segment. Complete characterization of a domain requires characterization of all SCSI bus segments in the domain. Figure 1 Driver-receiver connection Dr = Driver CircuitRc = Receiver CircuitDevice A to Device B driver-receiver connectionDevice B to Device A driver-receiver connectionDrRc27 signals (2 wires per signal on a differential bus) one signal shownDrRcDevice A Device BINCITS TR-28-2002 (R2007)6 4.2 Typical configurations Domains are configurations, examples of which are shown in Figure 2, Figure 3, Figure 4,
