ANSI-INCITS-TR-37-2004.pdf

American National Standard Developed by INCITS Technical Report for Information Technology - Time-Limited Commands (TLC) INCITS TR-37-2004 INCITS TR-37-2004 Copyright American National Standards Institute Provided by IHS under license with ANSI Licensee=USN Ship Repair Facility Yokosuka/9961031100 Not for Resale, 05/08/2007 21:15:35 MDTNo reproduction or networking permitted without license from IHS -,-,- Copyright American National Standards Institute Provided by IHS under license with ANSI Licensee=USN Ship Repair Facility Yokosuka/9961031100 Not for Resale, 05/08/2007 21:15:35 MDTNo reproduction or networking permitted without license from IHS -,-,- INCITS TR-37-2004 INCITS Technical Report for Information Technology Time-Limited Commands (TLC) Secretariat Information Technology Industry Council Abstract The purpose of the Time-Limited Commands (TLC) feature set is to define a mode of operation that bal- ances streaming performance with reliability. Copyright American National Standards Institute Provided by IHS under license with ANSI Licensee=USN Ship Repair Facility Yokosuka/9961031100 Not for Resale, 05/08/2007 21:15:35 MDTNo reproduction or networking permitted without license from IHS -,-,- Published by American National Standards Institute 25 West 43rd Street, New York, New York 10036 Copyright 2004 by Information Technology Industry Council (ITI) All rights reserved. No part of this publication may be reproduced in any form, in an electronic retrieval system or otherwise, without prior written permission of the publisher. Printed in the United States of America INCITS Technical Report Series This Technical Report is one in a series produced by the International Committee for Information Technology Standards (INCITS). The secretariat for INCITS is held by the Information Technology Industry Council (ITI), 1250 Eye Street, NW, Suite 200, Washington, DC 2005. As a by-product of the standards development process and the resources of knowledge devoted to it, INCITS from time to time produces Technical Reports. Such Technical Reports are not standards, nor are they intended to be used as such. INCITS Technical Reports are produced in some cases to disseminate the technical and logical concepts reflected in standards already published or under development. In other cases, they derive from studies in areas where it is found premature to develop a standard due to a still changing technology, or inappropriate to develop a rigorous standard due to the existence of a number of viable options, the choice of which depends on the users particular requirements. These Technical Reports, thus, provide guidelines, the use of which can result in greater consistency and coherence of information processing systems. When the draft Technical Report is completed, the Technical Committee approval process is the same as for a draft standard. Processing by INCITS is also similar to that for a draft standard. Patent Statement CAUTION: The developers of this Technical Report have requested that holders of patents that may be required for the implementation of the standard, disclose such patents to the publisher. However, neither the developers nor the publisher have undertaken a patent search in order to identify which, if any, patents may apply to this Technical Report. As of the date of publication of this Technical Report and following calls for the identification of patents that may be required for the implementation of the Technical Report, no such claims have been made. No further patent search is conducted by the developer or the publisher in respect to any Technical Report it processes. No representation is made or implied that licenses are not required to avoid infringement in the use of this Technical Report. Copyright American National Standards Institute Provided by IHS under license with ANSI Licensee=USN Ship Repair Facility Yokosuka/9961031100 Not for Resale, 05/08/2007 21:15:35 MDTNo reproduction or networking permitted without license from IHS -,-,- i Contents Page Foreword .iii Introduction v 1Scope . 1 1.1Assumptions 1 2Normative references. 1 2.1Approved references 1 2.2References under development. 1 2.3Other references 1 3Definitions, abbreviations, and conventions. 2 3.1Definitions and abbreviations. 2 3.1.1AbortMode . 2 3.1.2CCTL 2 3.1.3Command Timer 2 3.1.4DWE. 2 3.1.5NormalMode 2 3.1.6Qualified TLC command 2 3.1.7Re-arm the timer 2 3.1.8RC 2 3.1.9ReadContinuous Mode 2 3.1.10SE 2 3.1.11Timer armed. 2 3.1.12Timer expired. 2 3.1.13Timer running. 3 3.1.14TLC Mode 3 3.1.15WC. 3 3.1.16WriteContinuous Mode 3 3.2Conventions. 3 3.2.1Conventions are defined elsewhere. 3 4Description of the Feature Set. 4 4.1TLC feature set 4 4.2Command Completion Timer. 4 4.3Commands Affected 4 4.4Operational Summary 4 4.4.1Host Behavior 4 4.4.2Device Behavior. 5 4.5State Diagrams 6 4.5.1Time-Limited Command Overview. 6 4.5.2Time-Limited Flush Cache Command . 8 4.5.3TLC Error Handling 10 4.6Changes to Host Adapter Registers 13 4.6.1Error register 13 Copyright American National Standards Institute Provided by IHS under license with ANSI Licensee=USN Ship Repair Facility Yokosuka/9961031100 Not for Resale, 05/08/2007 21:15:35 MDTNo reproduction or networking permitted without license from IHS -,-,- ii Page 4.7Changes to Commands. 13 4.7.1Commands Affected 13 4.7.2FLUSH CACHE . 14 4.7.3FLUSH CACHE EXT . 15 4.7.4IDENTIFY DEVICE 17 4.7.5READ DMA 18 4.7.6READ DMA EXT 19 4.7.7READ LOG EXT 21 4.7.8SET FEATURES 22 4.7.9WRITE DMA 23 4.7.10WRITE DMA EXT 24 Figures 1TLC Overview State Diagram 6 2TLC Flush Cache State Diagram. 8 3TLC Error Handling State Diagram 10 Copyright American National Standards Institute Provided by IHS under license with ANSI Licensee=USN Ship Repair Facility Yokosuka/9961031100 Not for Resale, 05/08/2007 21:15:35 MDTNo reproduction or networking permitted without license from IHS -,-,- iii Foreword (This foreword is not part of INCITS Technical Report INCITS TR-37-2004.) This technical report describes the Time-Limited Commands (TLC) feature. This technical report was developed by T13 during 2004. The approval process start- ed in 2004. This document is not an American National Standard and the material contained herein is not normative in nature. Comments on the content of this document should be sent to the INCITS Secretariat, Information Technology Industry Council, 1250 Eye Street, NW, Suite 200, Washington, DC 20005. This technical report was processed and approved for submittal to ANSI by the Inter- National Commitee for Information Technology Standards, INCITS. Committee ap- proval of the technical report does not necessarily imply that all committee members voted for approval. At the time it approved this technical report, the INCITS Commit- tee had the following members: Karen Higginbottom, Chair Jennifer Garner, Secretary Organization RepresentedName of Representative Apple Computer, Inc.David Michael Farance, IncFrank Farance Hewlett-Packard Company.Karen Higginbottom Scott Jameson (Alt.) Steve Mills (Alt.) EIAEdward Mikoski, Jr. Suan Hoyler (Alt.) EMC2 .Gary Robinson IBM Corporation .Ronald F. Silletti Institute for Certification of Computer Professionals.Kenneth M. Zemrowski Thomas Kurihara (Alt.) IEEE .Judith Gorman Richard Holleman (Alt.) Robert Pritchard (Alt.) Intel Corporation.Philip Wennblom Dave Thewlis (Alt.) Norbert Mikula (Alt.) Microsoft Corporation .Mike Ksar Don Stanwyck (Alt.) Isabelle Valet-Harper (Alt.) National Institute of Standards 2. may enter this mode by executing a SET FEATURES command to set a non-zero value for a CCTL; 3. may execute a SET FEATURES command to specify the action to be taken by the device if a command does not complete within the define time window (e.g. abort or continue with bad data: ReadContinuous (RC) / WriteContinuous (WC) option) 4. shall arm the timer for the first group of commands by executing a FLUSH CACHE EXT command, knowing that the timer does not start until the host sends the first qualified READ or WRITE command to the device; 5. shall execute each group of commands with this protocol: a. execute a qualified READ or WRITE command on the device. The first such command after a FLUSH CACHE EXT command starts the Command Completion Timer. b. execute any group of commands to the device. The number and type of commands in this group depends on the expected average completion time (for the specific commands on this specific device) and on the selected CCTL value; Copyright American National Standards Institute Provided by IHS under license with ANSI Licensee=USN Ship Repair Facility Yokosuka/9961031100 Not for Resale, 05/08/2007 21:15:35 MDTNo reproduction or networking permitted without license from IHS -,-,- INCITS TR-37-2004 5 c. expect that the group of READ and/or WRITE qualified commands shall complete before the time limit expires. Commands other than those listed above shall not be affected by the CCTL. d. complete the execution of a FLUSH CACHE EXT command BEFORE the expiration of the time limit. This shall stop and re-arm the time for the next group of commands. If the timer expires DURING a Flush Cache command, the buffered data is not guaranteed to still be in the buffer. It should be considered as lost or destroyed. The host should re-issue all writes sent since the last FLUSH CACHE EXT command. 4.4.2 Device Behavior When this feature is supported by the device: 1. on completion of a FLUSH CACHE command shall stop the Command Completion Timer, re-arm it, but not allow it to run; 2. shall start the Command Completion Timer on receipt of the first qualified READ or WRITE command after a FLUSH CACHE EXT command 3. shall not allow the Command Completion Timer to affect the outcome of commands other than those listed above; 4. all qualified commands must complete before the CCTL expires. If the command cannot complete because of retries (or any other reason), it shall be terminated (either aborted or finished with incorrect data).The data returned may include the bad sector. 5. On receipt of a Power-on Reset or Hard Reset, the Stream Error logs (21h and 22h) shall be cleared of all recorded events. 6. On receipt of a Soft Reset, the Stream Error logs are unaffected. When this feature is not supported or not enabled (e.g. Normal mode): 1. The WorstCase timer and the ReadContinuous (RC) / WriteContinuous (WC) option are ignored (or not even implemented). 2. All configured retries shall be executed before an error is returned to the host. 3. If a Read command cannot complete because of retries, the data returned may include the bad sector. Copyright American National Standards Institute Provided by IHS under license with ANSI Licensee=USN Ship Repair Facility Yokosuka/9961031100 Not for Resale, 05/08/2007 21:15:35 MDTNo reproduction or networking permitted without license from IHS -,-,- INCITS TR-37-2004 6 4.5 State Diagrams 4.5.1 Time-Limited Command Overview TLC Off TLC0: New Cmd Received TLC1: TLC supported and Enabled TLC2: Qualified TLC Cmd TLC9: Done TLC3: Start Timer TLC4: Execute TLC Command TLC5: Execute Cmd ReadDMA ReadDMAExt WriteDMA WriteDMAExt TLC Supported and Enabled Timer Expired Before Cmd Started Timer Running Timer Not running Timer Expired During Cmd Timer Not Expired FlushCache FlushCacheExt Any Other Cmd TLC1:TLC5 TLC1:TLF0 TLC0:TLC5 TLC0:TLC1 TLC3:TLC4 TLC2:TLC3 TLC4:TLER0 TLC1:TLC2 TLC2:TLC4 TLC5:TLC9 TLC4:TLC9 TLC2:TLER0 TLER9:TLC9 TLF9:TLC9 Figure 1 - TLC Overview State Diagram Copyright American National Standards Institute Provided by IHS under license with ANSI Licensee=USN Ship Repair Facility Yokosuka/9961031100 Not for Resale, 05/08/2007 21:15:35 MDTNo reproduction or networking permitted without license from IHS -,-,- INCITS TR-37-2004 7 TLC0: New Cmd Received: This state is entered when the device receives a new command from the host. Transition TLC0:TLC1: This transition shall be taken if TLC mode is both supported and enabled. Transition TLC0:TLC5: TLC mode is either not supported or not enabled. TLC1: TLC supported and enabled: This state is entered when TLC mode is both supported and enabled. Transition TLC1:TLF0: The command is either FLUSH CACHE or FLUSH CACHE EXT Transition TLC1:TLC2: The command is either READ DMA, READ DMA EXT, WRITE DMA, or WRITE DMA EXT. Transition TLC1:TLC5: The command is not a qualified TLC command. TLC2: Qualified TLC Cmd: The command is known to be a Read or Write command that is affected by TLC feature set. Transition TLC2:TLC3: If the timer is not running, the timer shall be started. Transition TLC2:TLC4: If the timer is already running, the command shall be executed. Transition TLC2:TLER0: If the timer has expired, Time-Limited error handling shall take place. TLC3: Start Timer: Prior to entering this state, the timer has been loaded with the appropriate value. The timer is now started. Transition TLC3:TLC4: The command shall be executed. TLC4: Execute TLC Cmd: The command shall be executed. The timer shall be checked at times during execution. Transition TLC4:TLC9: The timer did not expire during the execution of the command. Transition TLC4:TLER0: The timer expired during the execution of the command. Time-Limited error handling shall take place. TLC5: Execute Other Cmd: The command shall be executed without checking the timer either before, during or after execution. This state of the timer is not affected. Transition TLC5:TLC9: Proceed to Normal end-of-command. TLC9: Done: Normal end-of-command processing happens here. Copyright American National Standards Institute Provided by IHS under license with ANSI Licensee=USN Ship Repair Facility Yokosuka/9961031100 Not for Resale, 05/08/2007 21:15:35 MDTNo reproduction or networking permitted without license from IHS -,-,- INCITS TR-37-2004 8 4.5.2 Time-Limited Flush Cache Command Timer Not Expired TLF0: TLC Flush Cache No data to flush TLF4: Execute Flush TLF9: Finish Flush TLF3: Pre-Check Timer TLF5: Post-Check Timer Timer Expired TLF0:TLF3 TLF3:TLER0 TLF3:TLF4 TLF4:TLF5 TLF5:TLER0 TLF0:TLF9 TLF9:TLC9 TLF5:TLF9 Timer Expired Timer Not Expired Return to TLC Overview TLER9:TLF9 Figure 2 - TLC Flush Cache State Diagram Copyright American National Standards Institute Provided by IHS under license with ANSI Licensee=USN Ship Repair Facility Yokosuka/9961031100 Not for Resale, 05/08/2007 21:15:35 MDTNo reproduction or networking permitted without license from IHS -,-,- INCITS TR-37-2004 9 TLF0: TLC Flush Cache: While in TLC Mode, a FLUSH CACHE o