2002.10.23 1 idema – japan discussion summary of av commands for ata-7 consumer hdd committee...

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2002.10.23

IDEMA – JAPANDiscussion summary of AV commands for ATA-7

Consumer HDD Committee

22th/August/2002

26th/June/2002

23th/October2002

2

2002.10.23

Intention of IDEMA-JAPAN

• IDEMA-JAPAN consumer HDD committee appreciates T-13 activities.

• Set box manufacturing companies of the committee member really need to standardize AV command. To reject confusion and to get compatibility of alternate or future HDD.

• IDEMA-JAPAN consumer HDD committee agrees basic concept of current ATA-7 AV commands. However IDEMA-JAPAN consumer HDD committee requests some modification to avoid misunderstanding as well as to use them effectively.

• IDEMA-JAPAN understand Command completion within the Time Limit should always have priority.

• These comments to follow are discussed by IDEMA-JAPAN consumer HDD committee's Sub WG members;

Toshiba, Hitachi, JVC, Matsushita, Sanyo, SONY, Pioneer

Maxtor Japan, Seagate Japan, Western Digital Japan, Japan IBM

Fujitsu,

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2002.10.23

Outline of IDEMA-JAPAN’s 8/20-22 proposal

Command bit IDEMA- J APAN CommentsGeneral Remain & additioal comments

A/ R Remain

R/ W Remain refer to 4.17.1

Stream ID Remain

Timer Limit Remain & additioal comments

AU Remain

URG Delete

RC Modify

NS Remain

HSE Remain

Stream ID Remain & additioal comments

Timer Limit Remain & additioal comments

URG Delete

WC Modify

F Remain

HSE Delete

Stream ID Remain & additioal comments

Timer Limit Remain additioal comments

Configure Stream

Write Stream DMA/ PIO

Read Stream DMA/ PIO8/22

8/22

8/22

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CONFIGURE STREAM

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T13 Draft Page 61

IDEMA Japan RequestsAdd annotation;

5.8.8 Description

If CONFIGURE STREAM was not issued, refer 4.17.1 Streaming commands 2nd paragraph and 5.37.4 Features register previous.

Reason for IDEMA Japan RequestsTo eliminate ambiguity.

Ex) If stream command was used without setting CONFIGURE STREAM, READ/WRITE Stream properties was preference and work well.

CONFIGURE STREAM

4.17.1 Streaming commands 2nd paragraph Page 40

If the host does not use a CONFIGURE STREAM command, the device shall use the time specified in each streaming command. The streaming commands may access any user LBA on a device. These commands may be interspersed with non-streaming commands, but there may be an impact on performance due to the unknown time required to complete the non-streaming commands.

5.37.4 Features register previous. Page 195

If the value is zero, the device shall use the Default Command Completion Time Limit supplied with a previous Configure Stream command for this Stream ID. If the Default Command Completion Time Limit is zero, or no previous Configure Stream command was defined for this Stream ID, the result is vendor specific.

5.8 CONFIGURE STREAM

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2002.10.23

T13 Draft 1

A/R specifies a request to add a new stream if set to one. If cleared to zero, a request to remove a previous configured stream is specified.

IDEMA Japan RequestsAgree

Reason for IDEMA Japan Requests

None

CONFIGURE STREAM – Register Bit 7 : A/R

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T13 Draft Page 61

R/W specifies a read stream if cleared to zero and a write stream if set to one.

IDEMA Japan Requests

It is necessary to clarify whether an individual stream ID can be configured as read and write streams concurrently or not.

Ex) Case 1.If yes: Configure ID1 Read with CCTL1-> Configure ID1 Write with CCTL2=> ID1 Read with CCTL1 and ID1 Write with CCTL2

Case 2.If No: Configure ID1 Read with CCTL1-> Configure ID1 Write with CCTL2=> ID1 Write with CCTL2 Only

Case 1 is requested.

CONFIGURE STREAM – Register Bit 6 : R/W

Reason for IDEMA Japan Requests Understanding bellow

Read Write

Content-1ID1

CCTL1

ID1CCTL2

Content-2ID2

CCTL3

ID2CCTL4

Read Write

Content-1ID1

CCTL1

ID2CCTL2

Content-2ID3

CCTL3

ID4CCTL4

× ○

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CONFIGURE STREAM – Register Bit 6 : R/W

IDEMA Japan Requests

Read Write

Content-1ID1

CCTL1

ID1CCTL2

Content-2ID2

CCTL3

ID2CCTL4

Read Write

Content-1ID1

CCTL1

ID2CCTL2

Content-2ID3

CCTL3

ID4CCTL4

○ ○IDEMA-JAPAN wants to use that one content is allowed to assign 1 stream ID.

The reason is 1. HDD wants to recognize the difference between following Read after Write with same stream and simultaneously Read and Write with a different stream.

2.Host think easy operation will be allowed regarding handle of stream ID,

because the rule which is not flexible makes a stream command hard to use

8/22

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2002.10.23

T13 Draft Page 61

R/W specifies a read stream if cleared to zero and a write stream if set to one.



None

CONFIGURE STREAM – Register Bit (2:0) : Stream ID

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2002.10.23

T13 Draft Page 61

The default command completion time limit. The value is calculated as follows:

(Default command completion time limit) = ((content of the Features register) (IDENTIFY DEVICE words (99:98))) seconds

IDEMA Japan RequestsIf improper CCT value was issued, additional error report need to be define.


If command completion time limit is too small to complete a command, all data will be returned as error. That makes contradiction.

CONFIGURE STREAM – Register Bit (7:0) : Timer Limit

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The processing way for the Improper Command Completion Time

Case 1

- Reject the improper value as compared with a guideline

Case 2

- Report as an error after command execution

ex.

If this type error occurs in Read Stream DMA/PIO mode or

Write Stream DMA/PIO mode, we understand the error status

is SE=0 ERR=1

Now IDEMA-JAPAN feel case 2 is better,because it is difficult to decidea proper guideline

8/22

8/22 IDEMA-JAPAN propose new error bit “CCTO”(Command Completion Time Limit OUT).CCTO bit is defined at bit “0” in Error register.

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2002.10.23

T13 Draft Page61

Sector Count Current -

The size of an Allocation Unit in sectors (bits 7:0).

Sector Count Previous -

The size of an Allocation Unit in sectors (bits 15:8).



None

READ STREAM DMA/PIO – Register Bit 7 : AU

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READ STREAM DMA/PIO

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T13 Draft 　 Page195/Page199

URG specifies an urgent transfer request. The Urgent bit specifies that the command should be completed in the minimum possible time by the device and shall be completed within the specified Command Completion Time Limit.

IDEMA Japan Requests/Comment

Definition of “minimum possible time” is necessary.

Is there any specific reason for URG bit?

Reason for IDEMA Japan Requests/Comment

Implication of “minimum possible time” is not clearly defined.

IDEMA Japan CE members may not use URG bit.

Does it mean “without error recovery”?

If so, “with hidden error recovery” or “without hidden error recovery”?

If not, what is the difference of URG and RC?

READ STREAM DMA/PIO – Register Bit 7: URG

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T13 Draft Page195/Page199

RC specifies Read Continuous mode enabled. If the RC bit is set, the device shall transfer the requested amount of data to the host within the Command Completion Time Limit even if an error occurs. The device may transfer unspecified data in an attempt to meet the Command Completion Time Limit. If the Command Completion Time Limit expires, the device shall terminate the data transfer. If the RC bit is clear, the device shall stop on an error.


1. RC specifies Read Continuous mode enabled. If the RC bit is set, the device shall transfer the requested amount of data to the host within the Command Completion Time Limit with error recovery even if an error occurs. The device may transfer unspecified data in an attempt to meet the Command Completion Time Limit. If the Command Completion Time Limit expires, the device shall terminate the data transfer. If the RC bit is clear, the device shall transfer the correct data to the host within the Command Completion Time Limit with error recovery. the device shall stop on an error.. If the Command Completion Time Limit expires, the device shall terminate the data transfer.

2. Command completion within the Time Limit should always have priority. Description of ABRT should include Command Completion Time Out Error case and new bit definition for Command Completion Time Out Error should be assigned.

Reason for IDEMA Japan Requests/CommentThe device shall always transfer correct data to the host as much as possible.

READ STREAM DMA/PIO – Register Bit 6: RC

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Explain READ STREAM DMA/PIO

RC=1 : transfer the requested amount of data SE=1,ERR=0

requested amount of data

XError

transfer correct dataIf error recovery don’t success, device may transfer unspecified data

RC=0 : transfer correct data SE=0,ERR=1 requested amount of data

transfer correct data If error recovery success,device transfer correct data.

If error recovery don’t success,device don’t transfer the data.

XError


transfer correct data

CCT

no error

Normal case (RC=1 or RC=0)

Device status become ready at the beginning of next CCT period


Try error recovery until CCT


unspecified data = include incorrect data

CCT

CCT

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Our definition of error recovery

Error recovery

Attempt to transfer the requested amount of correct

data exactly,or receive the requested amount of all data

as much as possible within the Command Completion

Time Limit expires

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(Not Sequential) may be set to one if the next read stream command with the same Stream ID may not be sequential in LBA space.


NS may not be needed.


Implication and effect of NS is not clearly defined.

READ STREAM DMA/PIO – Register Bit 5: NS

efficient by command pre-fech and 2 stream R/W caseIs Command pre-fech standard? 　→　 Now standard

8/22

8/22 IDEMA-JAPAN agree using NS bit.

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(Handle Streaming Error) specifies that this command starts at the LBA of the last reported error for this stream, so the device may attempt to continue its corresponding error recovery sequence where it left off earlier.


Effective.


Effective for IT data with READ STREAM DMA/PIO.

READ STREAM DMA/PIO – Register Bit 4: HSE

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READ STREAM DMA/PIO – Register Bit (2:1): Stream ID


Stream ID specifies the stream to be read.


If a Stream ID that is different from the pre-defined Stream ID by CONFIGURE STREAM command is specified, the device shall ignore the specified Stream ID.


If a specified Stream ID is different from the pre-defined Stream ID defined by previous CONFIGURE STREAM command, the device shall ignore the newly specified Stream ID.

This sentence need to re-consider in idema-japanClarify idema-japan request

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RC=0 : transfer correct data SE=0,ERR=1 requested amount of data

transfer correct data If error recovery succeed,device transfer correct data.

If error recovery don’t succeed,device don’t transfer the data.

XError



CCT

HSE=1

What is “HSE” operation

X X

ErrorRecovery

TransferCorrectdata

Only ErrorRecovery again ? →suppose Vendor Specific

Error Log EntryStream IDStarting Error LBA address

Read Stream DMA/PIO withHSE=1 or 0

Read Stream DMA/PIOwith HSE=1

using

CCT

CCTCCT

8/22

Even if stream ID is not defined,We suppose read command error recovery processIs performed from the beginning of latest error position,because of read stream command after error occurredhas include the error LBA number.And a host manages streams essentially

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WRITE STREAM DMA/PIO

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T13 Draft Page321/Page 325

URG specifies an urgent transfer request.The Urgent bit specifies that the command should be completed in the minimum possible time by the device and within the specified Command Completion Time Limit.

IDEMA Japan Requests/Comment Definition of “minimum possible time” is necessary.

Is there any specific reason for URG bit?


Implication of “minimum possible time” is not clearly defined.

IDEMA Japan CE members may not use URG bit.

Does it mean “without error recovery”?

If so, “with hidden error recovery” or “without hidden error recovery”?

If not, what is the difference of URG and WC?

WRITE STREAM DMA/PIO – Register Bit 7: URG

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WC specifies that the Write Continuous mode enabled.If the WC bit is set to one and an error occurs, the device shall transfer all of the data for the command without stopping to post an error.If the WC bit is cleared to zero and an error occurs, the device may stop transferring data.

IDEMA Japan Requests/Comment1. WC specifies Write Continuous mode enabled. If the WC bit is set, the device shall

receive the requested amount of data from the host within the Command Completion Time Limit even if an error occurs. The device shall receive requested amount of data even if the received data may be abandoned.And the status of device shall become ready after receiving the requested amount of data. When an error occurs, SE=1, ERR=0. If the device can not receive the data for impossible CCT value is issued,error status is SE=0,ERR=1. →SE=1,ERR=0 & Error log check

2. If the WC bit is clear, the device may stop to receive the data from the host if an error occurs. When an error occurs,SE=0,ERR=1.

3. Command completion within the Time Limit should always have priority. Description of ABRT should include Command Completion Time Out Error case and new bit definition for Command Completion Time Out Error should be assigned.


WRITE STREAM DMA/PIO – Register Bit 6: WC

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Explain WRITE STREAM DMA/PIO

WC=1 : receive the requested amount of data SE=1,ERR=0requested amount of data

XError

receive a part of data If error recovery don’t success, device receive data continuously.

Even if the received data may be abandoned In worst case

WC=0 : receive data SE=0,ERR=1requested amount of data

receive a part of data

XError


receive data

no error

Normal case (WC=1 or WC=0)


Device may stop to receive the data.


CCT

CCT

CCT

If error recovery success,device receive the data.

If error recovery don’t success,device may stop to receive the data.



How about treat Crc error ?

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F specifies that all data for the specified stream shall be flushed to the media before command complete is reported when set to one


effective


WRITE STREAM DMA/PIO – Register Bit 5: F

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HSE (Handle Streaming Error) specifies that this command starts at the LBA of the last reported error for this stream, so the device may attempt to continue its corresponding error recovery sequence where it left off earlier


Definition of “HSE” operation is necessary.


Basically “HSE” may not needed.

Generally the device can not understand “write error” without an action of “read after write“. And when the host will transfer its stream data to the device again, the host usually will transfer the requested amount of data.

Is there any specific reason for HSE bit?

WRITE STREAM DMA/PIO – Register Bit 4: HSE

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WRITE STREAM DMA/PIO – Register Bit 4: HSE

WC=0 : receive data SE=0,ERR=1requested amount of data

receive a part of data

XError


CCT

If error recovery success,device receive the data.

If error recovery don’t success,device may stop to receive the data.


8/22

HSE=1

X X

ErrorRecovery

TransferCorrectdata

Only ErrorRecovery again ? →suppose Vendor Specific

Error Log EntryStream IDStarting Error LBA address

Write Stream DMA/PIO withHSE=1 or 0

Write Stream DMA/PIOwith HSE=1

using

CCTCCT

Case-1 using HSE bit Drive may perform reallocation processCase-2 not using HSE bit Host system may use another area to dislikes the situation of error sectors only separated

→IDEMA-JAPAN thinks Case-2 is better

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2002.10.23


Stream ID specifies the stream to being written.


If a Stream ID that is different from the pre-defined Stream ID by CONFIGURE STREAM command is specified, the device shall ignore the specified Stream ID.


Undefined Stream ID shall be ignored.

WRITE STREAM DMA/PIO – Register Bit 3-1: Stream ID

今回の提案は Draft に直ぐには反映しない。McLean さんのまとめた資料を送るので、日本で継続検討して欲しい最終的には Draft に反映する　　

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If WC is set to one and an error occurs in the transfer or writing of

the data, the device shall continue to transfer and write all of the

requested data ・・　

6.69 WRITE STREAM DMA6.69.4 Inputs

and write means

All of the requested data will be written until CCTL was expired

The devide has finished to write all data to disk include Reallocation

(Problem : If reallocation area will be spend)

Therefore IDEMA-JAPAN thinks

- Usually host system dislikes the situation of error sectors only separated

- “and write” will be delete

- Processing include reallocation is Device vendor specific

- “ transfer “ is remain 　

2002.10.23 1 idema – japan discussion summary of av commands for ata-7 consumer hdd committee...

Documents

stream command

stream slide

idema japan requests

read stream

stream register

new stream

seagate japan

previous configured