Date post: | 16-Dec-2015 |
Category: |
Documents |
Upload: | avery-richmond |
View: | 236 times |
Download: | 0 times |
1
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,
3
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
5
2002.10.23
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
6
2002.10.23
T13 Draft Page 61
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
7
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.
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
× ○
8
2002.10.23
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
9
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.
IDEMA Japan RequestsAgree
Reason for IDEMA Japan Requests
None
CONFIGURE STREAM – Register Bit (2:0) : Stream ID
10
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.
Reason for IDEMA Japan Requests
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
11
2002.10.23
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.
12
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).
IDEMA Japan RequestsAgree
Reason for IDEMA Japan Requests
None
READ STREAM DMA/PIO – Register Bit 7 : AU
14
2002.10.23
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
15
2002.10.23
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.
IDEMA Japan Requests/Comment
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
16
2002.10.23
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
requested amount of data
transfer correct data
CCT
no error
Normal case (RC=1 or RC=0)
Device status become ready at the beginning of next CCT period
Device status become ready at the beginning of next CCT period
Try error recovery until CCT
Try error recovery until CCT
unspecified data = include incorrect data
CCT
CCT
17
2002.10.23
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
18
2002.10.23
T13 Draft Page195/Page199
(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.
IDEMA Japan Requests/Comment
NS may not be needed.
Reason for IDEMA Japan Requests/Comment
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.
19
2002.10.23
T13 Draft Page195/Page199
(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.
IDEMA Japan Requests/Comment
Effective.
Reason for IDEMA Japan Requests/Comment
Effective for IT data with READ STREAM DMA/PIO.
READ STREAM DMA/PIO – Register Bit 4: HSE
20
2002.10.23
READ STREAM DMA/PIO – Register Bit (2:1): Stream ID
T13 Draft Page195/Page199
Stream ID specifies the stream to be read.
IDEMA Japan Requests/Comment
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.
Reason for IDEMA Japan Requests/Comment
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
21
2002.10.23
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
Device status become ready at the beginning of next CCT period
Try error recovery until CCT
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
23
2002.10.23
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?
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 WC?
WRITE STREAM DMA/PIO – Register Bit 7: URG
24
2002.10.23
T13 Draft Page321/Page 325
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.
Reason for IDEMA Japan Requests/Comment
WRITE STREAM DMA/PIO – Register Bit 6: WC
25
2002.10.23
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
requested amount of data
receive data
no error
Normal case (WC=1 or WC=0)
Device status become ready at the beginning of next CCT period
Device may stop to receive the data.
Device status become ready at the beginning of next CCT period
CCT
CCT
CCT
If error recovery success,device receive the data.
If error recovery don’t success,device may stop to receive the data.
Try error recovery until CCT
Try error recovery until CCT
How about treat Crc error ?
26
2002.10.23
T13 Draft Page321/Page 325
F specifies that all data for the specified stream shall be flushed to the media before command complete is reported when set to one
IDEMA Japan Requests/Comment
effective
Reason for IDEMA Japan Requests/Comment
WRITE STREAM DMA/PIO – Register Bit 5: F
27
2002.10.23
T13 Draft Page321/Page 325
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
IDEMA Japan Requests/Comment
Definition of “HSE” operation is necessary.
Reason for IDEMA Japan Requests/Comment
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
28
2002.10.23
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
Device status become ready at the beginning of next CCT period
CCT
If error recovery success,device receive the data.
If error recovery don’t success,device may stop to receive the data.
Try error recovery until CCT
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
29
2002.10.23
T13 Draft Page321/Page 325
Stream ID specifies the stream to being written.
IDEMA Japan Requests/Comment
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.
Reason for IDEMA Japan Requests/Comment
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
30
2002.10.23
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