1、ANSI INCITS 311-1998 (R2003)(formerly ANSI NCITS 311-1998)for Information Technology Magnetic Tape Formatfor Information Interchange128-Track, Parallel Serpentine 12.65 mm(1/2 in), 3400 bpmm (86 360 bpi)Run Length Limited RecordingAmerican National Standardfor Information Technology Magnetic Tape Fo
2、rmatfor Information Interchange128-Track, Parallel Serpentine 12.65 mm(1/2 in), 3400 bpmm (86 360 bpi)Run Length Limited RecordingANSINCITS 311-1998SecretariatInformation Technology Industry CouncilApproved April 28, 1998American National Standards Institute, Inc.Approval of an American National Sta
3、ndard requires verification by ANSI thatthe requirements for due process, consensus, and other criteria for approvalhave been met by the standards developer.Consensus is established when, in the judgement of the ANSI Board ofStandards Review, substantial agreement has been reached by directly andmat
4、erially affected interests. Substantial agreement means much more thana simple majority, but not necessarily unanimity. Consensus requires that allviews and objections be considered, and that a concerted effort be madetowards their resolution.The use of American National Standards is completely volu
5、ntary; theirexistence does not in any respect preclude anyone, whether he has approvedthe standards or not, from manufacturing, marketing, purchasing, or usingproducts, processes, or procedures not conforming to the standards.The American National Standards Institute does not develop standards andwi
6、ll in no circumstances give interpretation on any American NationalStandard. Moreover, no person shall have the right or authority to issue aninterpretation of an American National Standard in the name of the AmericanNational Standards Institute. Requests for interpretations should beaddressed to th
7、e secretariat or sponsor whose name appears on the titlepage of this standard.CAUTION NOTICE:This American National Standard may be revised orwithdrawn at any time. The procedures of the American National StandardsInstitute require that action be taken periodically to reaffirm, revise, orwithdraw th
8、is standard. Purchasers of American National Standards mayreceive current information on all standards by calling or writing the AmericanNational Standards Institute.American National StandardPublished byAmerican National Standards Institute, Inc.11 West 42nd Street, New York, NY 10036Copyright 1998
9、 by Information Technology Industry Council (ITI)All rights reserved.No part of this publication 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 AmericaCAUTION:The developers of this standa
10、rd have requested that holders of patents that may be re-quired for the implementation of the standard disclose such patents to the publisher. However, nei-ther the developers nor the publisher have undertaken a patent search in order to identify which, ifany, patents may apply to this standard.As o
11、f the date of publication of this standard, following calls for the identification of patents thatmay be required for the implementation of the standard, notice of one or more such claims hasbeen received.By publication of this standard, no position is taken with respect to the validity of this clai
12、m or ofany rights in connection therewith. The known patent holder(s) has (have), however, filed a state-ment of willingness to grant a license under these rights on reasonable and nondiscriminatoryterms and conditions to applicants desiring to obtain such a license. Details may be obtained fromthe
13、publisher.No further patent search is conducted by the developer or publisher in respect to any standard itprocesses. No representation is made or implied that this is the only license that may be required toavoid infringement in the use of this standard.iContentsPageForeword.iv1Scope, purpose, and
14、application 11.1 Scope . 11.2 Purpose 11.3 Application 11.3.1 Conformance 12Normative references. 13Definitions. 24Tape characteristics . 65Recording. 65.1 Physical recording density 65.2 Bit-cell length 65.3 Average bit-cell length 65.3.1 Long-term average bit-cell length. 65.3.2 Short-term average
15、 bit-cell length 75.4 Bit rate of change . 75.5 Bit shift 75.6 Total character skew 75.7 Missing zero-crossing zones 75.8 Coincident missing zero-crossing zones 76Data track format 86.1 Number of data tracks 86.2 Track positions . 86.3 Track width. 106.4 Azimuth 106.5 Track identification . 107Tape
16、format 107.1 General. 107.2 Recording area. 107.3 Tach count 127.4 Physical blocks. 127.5 Servo acquisition region. 137.6 Volume control region 137.7 Data region. 137.8 Data entities . 148Packet format . 168.1 Packet header 178.2 Packet data 208.3 Packet trailer 209Device blocks . 209.1 Data device
17、blocks . 209.2 Mark device blocks. 219.3 Filemark mark. 21iiPage9.4 Void mark . 219.5 Beginning of half-wrap mark. 219.6 End of half-wrap mark 229.7 BOP mark. 229.8 EOD mark. 229.9 SDM mark 229.10 FID mark. 239.11 DBM mark 259.11.1 DBM general information packet 259.11.2 DBM wrap region packet 259.1
18、1.3 DBM partitions packet 269.11.4 DBM servo demark packet. 279.11.5 DBM filemark packet 289.12 SARS mark. 289.13 DBM checked out mark 289.14 DBM valid mark 2810Device block format 2910.1 Device block header. 2910.1.1 Device block control . 2910.1.2 Device block sequence control. 3210.1.3 Device blo
19、ck device information. 3210.2 Device block data. 3310.3 Device block trailer. 3311ECC 3311.1 CRC 3311.2 Code block . 3411.3 ECC-encoded code block. 3411.4 Codeword correction code generation . 3511.5 MIE pointer code generation 3611.6 ECC-encoded interleave unit . 3611.7 Short error correction code
20、generation. 3712Recording of bytes on tape 3912.1 Synchronization format. 3912.2 Interblock gap formatting 4212.3 RLL byte translation . 4212.4 Write equalization bit translation 4312.5 Writing bits on tape. 43Tables1Data Track Positions 92Track Identification . 103Region Dimensions 124Packet Types
21、195Device Block Types 316Sync Characters. 397RLL Encoder Table 438Write Equalizer Encoder Table. 43iiiPageFigures1Usable Recording Area 112Regions On Tape . 113Data Entities for Logical Block 154Data entities for device block 165Data Packet 166Mark Packet 177Device Block. 298Device Block Header 299C
22、RC 3410ECC-Encoded Code Block . 3511ECC 3612ECC-Encoded Interleave Unit 3713Positioning of SECC . 3814SECC odd bytes . 3815SECC even bytes . 3816Positioning of Synchronizing Features Beginning . 4017Positioning of Synchronizing Features End. 4018Placement of Synchronization Characters Beginning . 40
23、19Placement of Synchronization Characters Middle. 4120Placement of Synchronization Characters End . 4121Synchronization Characters for One- and Two-MIU Device Blocks . 4122Synchronization Characters for Three-MIU Device Block 42AnnexesAMeasurement of bit shift . 44A.1 Read equipment . 44A.2 Measurem
24、ent 45A.3 Data analysis 45BVendor code lists 46CBibliography 47ivForeword(This foreword is not part of American National Standard NCITS 311-1998.)This standard presents format and recording requirements for 12.65 mm (0.50 in)128-track magnetic tape to be used for information interchange among proces
25、singsystems, communication systems, and associated equipment. This standard dealssolely with recording on magnetic tape.The X3B5 Subcommittee on Digital Magnetic Tape, which developed this standard,consists of experienced and qualified specialists in manufacturing magnetic tape,and in recording digi
26、tal information on magnetic tape. This standard is the fourth toutilize this cartridge form factor and the first to use the new metal particle tape. Therecording format represents a significant advancement in reliability and volumetric ef-ficiency for 12.65 mm (0.50 in) magnetic tape. In the develop
27、ment of this standard,careful consideration was given to current practices, existing equipment and sup-plies, and the broadest possible acceptance, and to providing a basis for future im-provements in the use of the cartridge medium.There are three annexes in this standard. Annex A is normative and
28、is consideredpart of this standard. Annex B and annex C are informative and are not consideredpart of this standard.Requests for interpretation, suggestions for improvement or addenda, or defect reportsare welcome. They should be sent to National Committee for Information TechnologyStandards (NCITS)
29、, ITI, 1250 Eye Street, NW, Suite 200, Washington, DC 20005. This standard was processed and approved for submittal to ANSI by NCITS. Commit-tee approval of this standard does not necessarily imply that all members voted for itsapproval. At the time it approved this standard, NCITS had the following
30、 members:Karen Higginbottom, Chair(Vacant), Vice-ChairMonica Vago, SecretaryOrganization Represented Name of RepresentativeAMP, IncJohn HillCharles Brill (Alt.)Apple Computer, IncDavid K. MichaelJerry Kellenbenz (Alt.)AT VCR region; data region.Table 3 Region DimensionsDimension Minimum Nominal Maxi
31、mumd1 5.4 m (213 in)d2 8.0 m (315 in) 8.3 m (327 in) 8.6 m (339 in)d3 11.0 m (433 in) 11.4 m (449 in) 11.8 m (465 in)d4 2.0 m (79 in) d5 11.5 m (453 in)d6 17.8 m (701 in) d7 1.0 m (39 in) d8 2.5 m (98 in) d9 d8 d9 d8 d9 d8 d9d10 d9 d10 d9 d10 d9 d107.3 Tach countTwo tach counters provide information
32、 about the position of tape relative to the load point.Tach counter C is a 4-byte counter which is reset to 0000000016when the cartridge leader block isinserted into the machine reel. Tach counter C shall increment by 512 units for each 360 rotation of thecartridge reel when the tape is moved in the
33、 physical forward direction, and shall decrement by 512 unitsfor each 360 rotation of the cartridge reel when the tape is moved in the physical reverse direction.Tach counter M is a 4-byte counter which is reset to 0000000016when the cartridge leader block isinserted into the machine reel. Tach coun
34、ter M shall increment by 512 units for each 360 rotation of themachine reel when the tape is moved in the physical forward direction, and shall decrement by 512 unitsfor each 360 rotation of the machine reel when the tape is moved in the physical reverse direction. Thediameter of the machine reel wi
35、thout tape shall be 50.06 mm +0.00 mm, -0.05 mm (1.971 in +0.000 in,-0.002 in).The tach count shall be taken from tach counter C when tape is moving in the physical forward direction.The tach count shall be taken from tach counter M when tape is moving in the physical reverse direction.7.4 Physical
36、blocksInformation in the VCR and data regions is recorded on the media as one of two types of physical blocks:mark physical blocks and data physical blocks.A mark physical block contains no host data. It is used to indicate special conditions such as delimitersand format identification. The data con
37、tent of the mark physical block is described in clause 9.A data physical block contains logical block information.An interblock gap shall be recorded before and after each physical block.ANSI NCITS 311-199813The mark and data physical blocks are made up of the following entities: code block four-byt
38、e CRC; synchronization character; resynchronization burst; acquisition burst; synchronization burst interval; modulation triplet; modulation character.7.5 Servo acquisition regionThe servo acquisition region (SAQ) is used by the track following servo. The servo format is not specifiedby this standar
39、d. The servo acquisition region shall not contain recorded data information.7.6 Volume control regionThe volume control region (VCR) is located at the beginning of wrap 0 immediately following the servoacquisition region (SAQ). The VCR contains the following marks: format identification (FID) mark;
40、device block map (DBM) mark; statistical analysis and reporting system (SARS) mark; DBM Valid mark or DBM Checked Out mark. Format identification (FID) mark: The FID mark is the first entity recorded on the tape. The FIDidentifies the format that was used to write the data area of the physical volum
41、e. The FID is also thereference point from which distance along the tape is measured. Device block map (DBM) mark: The DBM mark immediately follows the FID mark and containsinformation which may be written and used by the system to determine the location of the partition, mediadefects, and recorded
42、elements. Statistical analysis and reporting system (SARS) mark: The SARS mark immediately follows the DBMmark. The SARS mark contains information about the performance of the tape. DBM Valid mark: The DBM Valid mark, if present, immediately follows the SARS mark. The presenceof the DBM valid mark i
43、ndicates that the DBM mark is valid. When a cartridge is opened, this mark isoverwritten by the DBM Checked Out mark. DBM Checked Out mark: The DBM Checked Out mark, if present, immediately follows the SARS mark.The presence of the DBM Checked Out mark indicates that the DBM mark is not valid. When
44、the cartridgeis closed, this mark is overwritten by the DBM Valid mark if the information in the DBM is accurate.7.7 Data regionThe data region is the portion of tape used to record data and marks. Nominally, it is located betweenlogical point 1 and logical point 2 for the outbound half-wraps, and b
45、etween logical point 2 and logical point3 for the inbound half-wraps.ANSI NCITS 311-199814All data and marks associated with the data region are contained within the area bounded by BOP andEOD. The data region contains the following entities: data physical block; BOP mark; BOW mark; EOW mark; EOD ma
46、rk; SDM mark; filemark mark; void mark; IBG.7.8 Data entitiesData to be recorded is sent from a host computer to the tape subsystem in the form of logical blocks.Refer to figure 3. The maximum logical block size is 2 MB (2 097 152 bytes). A four-byte CRC isappended to each logical block. This CRC is
47、 processed as part of the logical block data through allformatting processes and is recorded on the physical media.Logical blocks, with appended CRC, are broken into subblocks. The maximum subblock size is 224 KBplus 4 CRC bytes (229 380 bytes). If the logical block contains 224 KB or less, then a s
48、ingle subblock equal in size to the logical blockplus 4 CRC bytes is created. If the logical block contains more than 224 KB, subblocks are created as required for the number ofbytes in the logical block. Each subblock for a logical block, except the last subblock, shall contain 224KB. The last subb
49、lock may contain between 1 byte and 224 KB, plus 4 CRC bytes, inclusive.Subblocks may be processed.Each subblock, or processed subblock, is placed into one or two packets. The subblock is broken into twopackets only if the subblock data will not all fit into the current device block.Packets containing logical block data are formed from subblocks by concatenating a packet header, asubblock or portion of a subblock, and a packet trailer. Packets containing mark data are formed byconcatenating a packet header, the mark packet
