13. CD-ROM Devices
13.1. Model for CD-ROM Devices
CD-ROM devices permit reading data from a rotating media. Writing the media
is not supported. Data transfer can begin with any of the consecutively
numbered logical blocks. Data on CD-ROM devices is addressed the same as
usual (magnetic) direct-access devices. Some CD-ROM devices support a separate
information stream (e.g. audio and/or video but referred to as audio in this
section) transmitted via a connection other than the SCSI Bus. This device
type defines commands for controlling these other information streams.
CD-ROM drives are designed to work with any disc that meets the "Red Book"
or "Yellow Book" (IEC 908) documents at the current revision level. Many new
drives read CD-ROM data discs, digital audio discs, and audio-combined discs
(i.e. some tracks are audio, some tracks are data).
13.1.1. CD-ROM Media Organization
The formats written on the CD-ROM and CD-DA (Digital Audio) media require
special interfacing considerations.
NOTE: This section contains a number of terms which have special meanings
peculiar to CD-ROM technology or that may be unfamiliar to many readers of
this standard. The glossary (see 13.4.) defines these terms.
These discs may contain either audio, data or a mixture of the two. Table
13-2 shows the format of a audio-combined disc to illustrate the relationship
between the logical block addresses reported in SCSI and the MSF address
encoded on the media.
NOTE: The term frame is used in two different ways in the CD-ROM media
standard. The intended meaning can only be determined from the context.
Whenever possible, this description replaces the larger data unit with the
more familiar term "sector". The primary exception to this policy is the
use of frame when referring to the MSF address. In the MSF context, one
frame (F Field unit) equals one sector. On a typical two channel CD-DA
media, each frame (F Field unit) is played in 1/75th of a second.
The physical format defined by the CD-ROM media standards provides 2352
bytes per sector. For usual computer data applications, 2048 bytes are used
for user data, 12 bytes for a synchronization field, 4 bytes for a sector
address tag field and 288 bytes - the auxiliary field - for L-EC (CD-ROM Data
Mode 1). In less critical applications, the auxiliary field may also be used
for user data (CD-ROM Data Mode 2). A CD-ROM physical sector size is 2048,
2336 or 2340 bytes per sector. These values correspond to user data field
only, user data plus auxiliary data, the 4 byte address tag plus user data
plus auxiliary data.
Selection among these options is made by setting the density code field of
the MODE SELECT block Descriptor. The usual selection is 2048 bytes per
physical sector via a Density Code setting of 1. (See Table 13-32 CD-ROM
Density Code Values.)
This same area of the CD-ROM or CD audio media may store 1/75th of a second
of 2 channel audio information formatted according to the CD-DA specification.
(These audio channels are usually the Left and Right components of a stereo
pair.) An audio only density code value can be used to declare an area of the
media to be invalid for data operations.
Data sectors are addressed by their logical block address relative to the
first addressable block on the medium which is located at MSF address
00/02/00. This MSF address is the logical beginning of medium, and is
designated logical block zero.
Logical addressing of CD-ROM information may use any logical block length.
When the specified logical block length is an exact divisor or integral
multiple of the selected number of bytes per CD-ROM sector, the device shall
map one to one the bytes transferred from CD-ROM sectors to the bytes of
Logical Blocks. For instance, if 2048 bytes are transferred from each CD-ROM
sector (specified by the CD-ROM Density Code value, see Table 13-32), and the
logical block length is 512 bytes, then each CD-ROM sector shall map to
exactly four logical blocks. This standard does not define the mapping of
Logical Block lengths which do not evenly divide or are not exact multiples of
the selected number of bytes per CD-ROM sector.
A track may be viewed as a partition of the CD-ROM address space. A CD-ROM
media contains from one to ninety-nine tracks. All information sectors of a
track are required to be of the same type (audio or data) and mode. Each
change in the type of information on the disc requires a change in track
number. A disc containing both audio and data would have at least two tracks,
one for audio and one for data.
The tracks of a CD media are numbered consecutively with values between 1
and 99. However, the first information track may have a number greater than 1.
Tracks have a minimum length of 300 sectors including any transition area that
is part of a track.
The CD-ROM media standards require transition areas between tracks encoded
with different types of information. In addition, transition areas may be
used at the beginning or end of any track. For audio tracks the transition
areas are called pause areas. For data tracks transition areas are called
pre-gap and post-gap areas. See Table 13-2 for an example. The "Red Book"
and "Yellow Book" documents specify minimum time durations for these areas.
Maximum time durations are not specified.
Transition areas are formatted and the logical address continues to
increment through transition areas. Some media (i.e. discs with only one
track) may not have transition areas. The means to determine of the location
of the transition areas is vendor or application specific and is addressed by
other standards (e.g. ISO 9660).
CD-ROM is a unique SCSI device in the respect that some logical blocks on a
disc may not be accessible by all commands. SEEK commands may be issued to
any logical block address within the reported capacity of the disc. READ
commands cannot be issued to logical blocks that occur in some transition
areas, or to logical blocks within an audio track. PLAY commands cannot be
issued to logical blocks within a data track.
The blank verify (BlkVfy) option of the Verify command (15.2.11), for CD-ROM
devices, shall verify that the addressed blocks are transition area blocks.
CD-ROM media have lead-in and lead-out areas. These areas are outside of
the user accessible area as reported in the READ CD-ROM CAPACITY data. The
lead-in area of the media is designated track zero. The lead-out area is
designated track 0AAh. The sub-channel Q in the lead-in track contains a
table of contents (TOC) of the disc.
IMPLEMENTORS NOTE: The READ CD-ROM CAPACITY command returns the logical
block address of the last block prior to the lead-out area. This location
may be in a transition area and therefore not a valid address for read
operations.
The table of contents gives the absolute MSF location of the first
information sector of each track. Control information (audio/data, method of
audio encoding, etc.) for each track is also given in the TOC. However, the
TOC does not distinguish between the different modes of data tracks (i.e. CD-
ROM Data Mode one vs. CD-ROM Data Mode two).
The MSF locations of the beginning of data tracks in the TOC are required to
be accurate, however, the TOC values for audio tracks have a tolerance of plus
or minus 75 sectors. Information from the TOC can be used to reply to a READ
CD-ROM CAPACITY command. When this is done the drive implementor should
consider the possible tolerances and return a value which allows access to all
information sectors.
An index is a partition of a track. Pre-gap areas are encoded with an index
value of zero. Pause areas at the beginning of audio tracks are also encoded
with an index value of zero. The first information sector of a track has
index value of one. Consecutive values up to 99 are permitted. Index
information is not contained in the TOC. Not all sectors are encoded with the
index value in the Q-sub- channel data (the requirement is 9 out of 10). A
sector without an index value is presumed to have the same index as the
preceding sector.
Tracks and indexes are not defined to be any particular length. (Except for
a minimum track length of 300 sectors.) A CD disc may be created with a
single information track with a single index or with 99 information tracks
each with 99 indexes.
The sub-channel information which is part of each sector includes a track
relative MSF location value giving the distance from the first information
sector of the track. On the media this value decreases during the pre-gap area
(sectors with index values of 0) and increases for the rest of the track. The
data returned by the READ SUB-CHANNEL command with MSF bit set to zero,
converts this to a track relative logical block address (TRLBA). The TRLBA is
continually increasing over the whole track and pre-gap areas shall return
negative values. When the MSF bit in the Read Sub-channel command is set to
one, the MSF track relative location value from the media is reported without
change.
13.1.2. CD-ROM Physical Data Format
The physical format of CD-ROM and CD-DA media uses a smaller unit of
synchronization than the more familiar magnetic or optical recording systems.
The basic data stream synchronization unit is a small frame. This is not the
same large frame (sector) as referred to in the MSF unit. Each small frame
consists of 588 bits. A sector on CD-ROM media consists of 98 small frames.
A CD-ROM small frame consists of:
1 Synchronization pattern (24+3 bits)
1 Byte of Sub-channel Data (14+3 bits)
24 Bytes of Data (24 x (14+3) bits)
8 Bytes of CIRC code (8 x (14+3) bits) Total: 588 bits.
Data, sub-channel and CIRC bytes are encoded with an eight-to-fourteen bit
code then three merging bits are added. The merging bits are chosen to
provide minimum low frequency signal content and optimize phase lock loop
performance.
13.1.2.1. Frame Format for Audio
Each small frame of an audio track on a two channel CD-DA or CD-ROM media
consists of six digitized 16 bit samples of each audio channel. These 24 bytes
of data are combined with a synchronization pattern, CIRC bytes and a sub-
channel byte to make a frame. Each frame takes approximately 136.05 uS to
play. This gives a sampling rate of 44.1 KHz for each channel. The sub-channel
information creates the higher level sector grouping for audio tracks.
13.1.2.2. Sector Format for Data
The data bytes of 98 small frames comprise the physical unit of data which
is referred to as a sector. (98 small frames times 24 bytes per small frame
equal 2352 bytes of data per sector.)
A sector which contains CD-ROM Data Mode one data has the following format:
12 bytes Synchronization Field
4 bytes CD-ROM data header
Absolute M Field in bcd format
Absolute S Field in bcd format
Absolute F Field in bcd format
CD-ROM Data Mode Field
2048 bytes User Data Field
4 bytes Error Detection Code
8 bytes zero
276 bytes Layered Error Correction Code
A sector which contains CD-ROM Data Mode two data has the following format:
12 bytes Synchronization Field
4 bytes CD-ROM Data Header
Absolute M Field in bcd format
Absolute S Field in bcd format
Absolute F Field in bcd format
CD-ROM Data Mode Field
2336 bytes User Data Field (2048 bytes of Mode 1 data plus 288 bytes of
Auxiliary data)
IMPLEMENTORS NOTE: Many drives are capable of returning CD-ROM Data Mode
one data in a CD-ROM Data Mode two format. This allows the user to
investigate the error detection and error correction codes. However data
encoded as CD-ROM Data Mode two cannot be read as CD-ROM Data Mode one data.
13.1.2.3. Sub-channel Information Formats
The Sub-channel byte of each frame is assigned one bit to each of the 8 sub-
channels, designated P, Q, R, S, T, U, V, W. Only sub-channels P and Q are
defined for CD-ROM media. The other sub-channel bits are zero.
Sub-channel P is a simple flag bit that may be used for audio muting control
and track boundary determination.
Sub-channel Q has a higher level of structure. All the sub-channel Q bits of
a sector define the sub-channel Q information block. (For audio tracks,
decoding the Q sub-channel is the only way to distinguish sector boundaries.)
The sub-channel Q block consists of 98 bits, one bit from each small frame
in a sector. Three formats are defined for the sub-channel Q information
block. The first format provides location information and is defined as
follows:
2 bits Sub-channel Synchronization Field
4 bits ADR Field - defines the format
4 bits Control field - defines the type of information in this sector.
8 bits Track Number (in BCD)
8 bits Index Number (in BCD)
24 bits Track Relative MSF address
8 bits reserved (0)
24 bits Absolute MSF address
16 bits CRC error detection code.
This format is required to exist in at least nine out of ten consecutive
sectors.
The second and third formats are optional. If used they must exist in at
least one out of 100 consecutive sectors. They include the absolute Frame
byte of the MSF address to provide location information continuity.
The second format gives the catalog number of the disc (UPC/EAN Bar Code
number). This information is constant over the whole media.
The third format gives the International-Standard-Recording-Code (ISRC) for
each track. The ISRC is defined in DIN-31-621. This format is not present on
lead-in or lead-out tracks and may change only after the track number changes.
13.1.3. CD Audio Error Reporting
PLAY AUDIO commands with the immediate bit set in the audio control mode
return status as soon as the command has been validated (which may involve a
seek to the starting address). The playback operation continues and may
complete without notification to the initiator. Error termination of audio
operations shall be reported to the initiator by returning immediate CHECK
CONDITION status to the next command (except for REQUEST SENSE and INQUIRY.)
The deferred error sense data error code, 71h (see Table 7-35 and 7.2.14.2.)
is used to indicate that the error is not due to the current command.
The status of the play operation may be determined by issuing a REQUEST
SENSE command. The sense key is set to NO SENSE and the play operation status
(see Table 13-20) is reported in the additional sense code qualifier field.
13.1.4. CD-ROM Ready Condition/Not Ready Condition
The ready condition occurs after a cartridge is inserted and the drive has
performed its initialization tasks. These may include reading the table of
contents from the media.
A not ready condition may occur for the following reasons:
(1) There is no cartridge inserted.
(2) The drive is unable to load or unload the cartridge.
(3) The drive is unable to recover the table of contents.
(4) The controller cannot select the drive.
13.1.5. CD-ROM Address Reporting Formats (MSF Bit)
Several CD-ROM specific commands can report addresses either in logical or
in MSF format (Table 13-1). The READ HEADER, READ SUB-CHANNEL and READ TABLE
OF CONTENTS commands have this feature.
An MSF bit of zero requests that the logical block address format be used
for the CD-ROM absolute address field or for the offset from the beginning of
the current track expressed as a number of logical blocks in a CD-ROM track
relative address field. This track relative logical block address (TRLBA)
value is reported as a negative value in twos-complement notation for
transition areas that have decreasing MSF encoded relative addresses.
An MSF bit of one requests that the MSF format be used for these fields. In
certain transition areas the relative MSF addresses are decreasing positive
values. The absolute MSF addresses are always increasing positive values (see
entry in 13.4).
Table 13-1: MSF Address Format
==============================================================================
Bit| 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 |
Byte | | | | | | | | |
==============================================================================
0 | Reserved |
-----|-----------------------------------------------------------------------|
1 | M Field |
-----|-----------------------------------------------------------------------|
2 | S Field |
-----|-----------------------------------------------------------------------|
3 | F Field |
==============================================================================
The M, S, and F fields are expressed as binary numbers. The values match
those on the media except for the encoding. The ratios of M field units to S
field units and S field units to F field units is reported in the mode
parameters page (see 13.3.3).
13.1.6. Sensing Support for CD-Audio Commands.
If any commands related to audio operations are implemented then the PLAY
AUDIO command shall be implemented to allow a method for the initiator to
determine if audio operations are supported. A target responding to a PLAY
AUDIO command which has a transfer length of zero with CHECK CONDITION status
and setting the sense key to ILLEGAL REQUEST does not support audio play
operations.
NOTE: The PLAY AUDIO command may be implemented without support for any of
the other audio operations commands.
Table 13-2 gives an example of a disc layout.
Table 13-2: Example Mixed Mode CD-ROM Disc Layout
The logical addresses given below assume a block length of 2048, 2336 or 2340
bytes. For block lengths of 1024, 512 or 256 multiply all values given in the
SCSI Address columns by 2, 4 or 8 respectively.
SCSI /--- Sub-channel Information ----\
Address / \
Logical Track Absolute Track Track Sector Mode CD-ROM
Address Relative MSF and Relative is Info Audio Data
Block (decimal) Logical Address Index MSF or is or Mode
Description Address (1) Address Pause Data (2)
-----------------------------------------------------------------------------
Lead-In
Area (3) --- --- --- 0/- --- --- Audio ---
Pre-gap (3) --- --- 00/00/00 1/0 00/02/00 Pause Data Null
1st Trk 0000 0 00/02/00 1/1 00/00/00 Info Data L-EC
Data (5) (4)
2nd Trk 6000 0 01/22/00 2/1 00/00/00 Info Data L-EC
Data (5) (4)
7500 1500 01/42/00 2/2 00/20/00 Info Data L-EC
Post-gap 9000 3000 02/02/00 2/3 00/40/00 Pause Data Null
Pause- 9150 -150 02/04/00 3/0 00/02/00 Pause Audio ---
Silence (9) (8)
3rd Trk 9300 0 02/04/00 3/1 00/00/00 Info Audio ---
Audio (7) (6)
11400 2250 02/34/00 3/2 00/30/00 Info Audio ---
Track 4 21975 0 04/53/00 4/1 00/00/00 Info Audio ---
Audio (7) (6)
Pre-gap 30000 -225 06/40/00 5/0 00/03/00 Pause Audio ---
Part 1 (9)
Pre-gap 30075 -150 06/41/00 5/0 00/02/00 Pause Data Null
Part 2
Track 5 30225 0 06/43/00 5/1 00/00/00 Info Data L-EC
Data
Last 263999 233774 58/39/74 5/1 51/56/74 Info Data L-EC
Info (10)
Post-gap --- 233775 58/40/00 5/2 51/57/00 Pause Data Null
Lead-out 264000 0 58/42/00 AA/1 00/00/00 Pause Audio ---
track (11) (12) (13)
Notes for Table 13-2:
(1) Absolute MSF address repeated in the header field of data blocks.
(2) The CD-ROM Data Mode is stored in the header of data tracks. This
indicates that the block is part of a data pre-gap or post-gap (null), that
this a data block using the auxiliary field for L-EC symbols (ECC - CD-ROM
Data Mode one), or that this is a data block using the auxiliary field for
user data (CD-ROM Data Mode two).
(3) Table of contents information is stored in the sub-channel of lead-in
area. The lead-in area is coded as track zero. Track zero and the initial 150
sector pre-gap (or audio pause) are not accessible with logical addressing.
(4) Value stored in table of contents with zero tolerance.
(5) Exact value returned by READ TOC command.
(6) Value stored in table of contents plus or minus 75 sectors.
(7) Value returned by READ TOC command plus or minus 75 blocks.
(8) Track relative MSF value decreases to 0 in pre-gap areas.
(9) Track relative logical addresses are negative in the pre-gap areas.
Pre-gap areas have index values of zero.
(10) Minimum value returned by READ CD-ROM CAPACITY - Exact value depends on
encoding of this track and the lead out track and whether this is derived from
the TOC data.
(11) Value returned by READ TOC command - exact if lead-out track is encoded
as data, or plus or minus 75 blocks if encoded as audio.
(12) Value stored in table of contents - exact if lead-out track is coded
as data, or plus or minus 75 blocks if coded as audio.
(13) Lead-out track number is defined as 0AAh.
13.1.7. Error Reporting
If any of the following conditions occur during the execution of a command
the target shall return CHECK CONDITION status. The appropriate sense key and
additional sense code should be set. The following table illustrates some
error conditions and the applicable sense keys. The table does not provide an
exhaustive enumeration of all conditions that may cause the CHECK CONDITION
status.
Condition Sense Key
---------------------------------------------- ----------------------------
Invalid logical block address ILLEGAL REQUEST
Unsupported option requested ILLEGAL REQUEST
Target reset or medium change since
last command from this initiator UNIT ATTENTION
Self diagnostic failed HARDWARE ERROR
Unrecovered read error MEDIUM ERROR
HARDWARE ERROR
Recovered read error RECOVERED ERROR
Overrun or other error that might
be resolved by repeating the command ABORTED COMMAND
Attempt to read a blank block. BLANK CHECK
Attempt to play a data block as audio. BLANK CHECK
In the case of an invalid logical block address, the sense data information
field shall be set to the logical block address of the first invalid address.
In the case of an attempt to read a blank or previously unwritten block, the
sense data information field shall be set to the logical block address of the
first blank block encountered. The data read up to that block shall be
transferred.
There are other special error situations for CD-ROM devices. In the
following cases the sense key shall be set to BLANK CHECK and the additional
sense code set to END OF USER AREA ENCOUNTERED ON THIS TRACK.
(1) A post-gap area is encountered. (i.e. a block with CD-ROM Data Mode 0.)
(2) A pre-gap area is encountered. (i.e. a block with index equal to 0.)
(3) The information type (data vs. audio) changes.
When not performing audio playback, if the logical block address requested
is not within a data track the command shall be terminated with CHECK
CONDITION status. The sense key shall be set to BLANK CHECK and the
additional sense code set to ILLEGAL MODE FOR THIS TRACK. This applies to
audio-combined and audio media.
13.2. Commands for CD-ROM Devices
The commands for CD-ROM devices shall be as shown in Table 13-3, and 13-4.
Table 13-3: Commands for CD-ROM Devices(1)
==============================================================================
Operation
Command Name Code Type Section
------------------------------------------------------------------------------
CHANGE DEFINITION 40h O 7.2.1
COMPARE 39h O 7.2.2
COPY 18h O 7.2.3
COPY AND VERIFY 3Ah O 7.2.4
INQUIRY 12h M 7.2.5
LOCK/UNLOCK CACHE 36h O 8.2.2
LOG SELECT 4Ch O 7.2.6
LOG SENSE 4Dh O 7.2.7
MODE SELECT(6) 15h O 7.2.8
MODE SELECT(10) 55h O 7.2.9
MODE SENSE(6) 1Ah O 7.2.10
MODE SENSE(10) 5Ah O 7.2.11
PAUSE/RESUME 4Bh O 13.2.1
PLAY AUDIO(10) 45h O* 13.2.2
PLAY AUDIO(12) A5h O* 13.2.3
PLAY AUDIO MSF 47h O* 13.2.4
PLAY AUDIO TRACK/INDEX 48h O* 13.2.5
PLAY TRACK RELATIVE(10) 49h O* 13.2.6
PLAY TRACK RELATIVE(12) A9h O* 13.2.7
PRE-FETCH 34h O 8.2.3
PREVENT/ALLOW MEDIUM REMOVAL 1Eh O 8.2.4
READ(6) 08h O 8.2.5
READ(10) 28h M 8.2.6
READ(12) A8h O 15.2.4
READ BUFFER 3Ch O 7.2.12
READ CD-ROM CAPACITY 25h M 13.2.8
READ HEADER 44h O 13.2.9
READ LONG 3Eh O 8.2.9
READ SUB-CHANNEL 42h O 13.2.10
READ TOC 43h O 13.2.11
RECEIVE DIAGNOSTIC RESULTS 1Ch O 7.2.13
RELEASE 17h M 8.2.11
REQUEST SENSE 03h M 7.2.14
RESERVE 16h M 8.2.12
REZERO UNIT 01h O 8.2.13
==============================================================================
Key: M = Command implementation is mandatory.
O = Command implementation is optional.
* = If any of the PLAY AUDIO commands (as indicated by an * in the
'Type' column in Table 13-3) are implemented, the PLAY AUDIO
command shall be implemented by the target.
Table 13-4: Commands for CD-ROM Devices(2)
==============================================================================
Operation
Command Name Code Type Section
------------------------------------------------------------------------------
SEARCH DATA EQUAL(10) 31h O 8.2.14.1
SEARCH DATA EQUAL(12) B1h O 15.2.8
SEARCH DATA HIGH(10) 30h O 8.2.14.2
SEARCH DATA HIGH(12) B0h O 15.2.8
SEARCH DATA LOW(10) 32h O 8.2.14.3
SEARCH DATA LOW(12) B2h O 15.2.8
SEEK(6) 0Bh O 8.2.15
SEEK(10) 2Bh O 8.2.15
SEND DIAGNOSTIC 1Dh M 7.2.15
SET LIMITS(10) 33h O 8.2.16
SET LIMITS(12) B3h O 15.2.9
START STOP UNIT 1Bh O 8.2.17
SYNCHRONIZE CACHE 35h O 8.2.18
TEST UNIT READY 00h M 7.2.16
VERIFY(10) 2Fh O 15.2.11
VERIFY(12) AFh O 15.2.12
WRITE BUFFER 3Bh O 7.2.17
==============================================================================
Key: M = Command implementation is mandatory.
O = Command implementation is optional.
The following command codes are vendor specific: 02h, 05h, 06h, 09h, 0Ch,
0Dh, 0Eh, 0Fh, 10h, 11h, 13h, 14h, 19h, 20h, 21h, 22h, 23h, 24h, 26h, 27h,
29h, and C0h through FFh. All remaining command codes for CD-ROM devices are
reserved for future standardization.
13.2.1. PAUSE RESUME Command
Table 13-5: PAUSE RESUME Command
==============================================================================
Bit| 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 |
Byte | | | | | | | | |
==============================================================================
0 | Operation Code (4Bh) |
-----|-----------------------------------------------------------------------|
1 | Logical Unit Number | Reserved |
-----|-----------------------------------------------------------------------|
2 | Reserved |
-----|-----------------------------------------------------------------------|
3 | Reserved |
-----|-----------------------------------------------------------------------|
4 | Reserved |
-----|-----------------------------------------------------------------------|
5 | Reserved |
-----|-----------------------------------------------------------------------|
6 | Reserved |
-----|-----------------------------------------------------------------------|
7 | Reserved |
-----|-----------------------------------------------------------------------|
8 | Reserved | Resume |
-----|-----------------------------------------------------------------------|
9 | Control |
==============================================================================
The PAUSE RESUME command (Table 13-5) requests that the device stop or start
an audio play operation. This command is used with PLAY AUDIO commands issued
while the immediate bit is set to one.
A resume bit of zero causes the drive to enter the hold track state with the
audio output muted after the current block is played. A resume bit of one
causes the drive to release the pause and begin play at the block following
the last block played.
If an audio play operation cannot be resumed and the resume bit is one, the
command is terminated with CHECK CONDITION status. If the resume bit is zero
and an audio play operation cannot be paused, (no audio play operation has
been requested, or the requested audio play operation has been completed) the
command is terminated with CHECK CONDITION status.
It shall not be considered an error to request a pause when a pause is
already in effect or to request a resume when a play operation is in progress.
13.2.2. PLAY AUDIO(10) Command
Table 13-6: PLAY AUDIO(10) Command
==============================================================================
Bit| 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 |
Byte | | | | | | | | |
==============================================================================
0 | Operation Code (45h) |
-----|-----------------------------------------------------------------------|
1 | Logical Unit Number | Reserved | RelAdr |
-----|-----------------------------------------------------------------------|
2 | (MSB) |
-----|--- ---|
3 | |
-----|--- Starting Logical Block Address ---|
4 | |
-----|--- ---|
5 | (LSB)|
-----|-----------------------------------------------------------------------|
6 | Reserved |
-----|-----------------------------------------------------------------------|
7 | (MSB) |
-----|--- Transfer Length ---|
8 | (LSB) |
-----|-----------------------------------------------------------------------|
9 | Control |
==============================================================================
The PLAY AUDIO command (Table 13-6) requests the target to begin an audio
playback operation. The command function (Immed and SOTC bits) and the output
of audio signals shall be as specified by the settings of the mode parameters
(see 13.3.3.1.).
If any commands related to audio operations are implemented then the PLAY
AUDIO command shall be implemented to allow a method for the initiator to
determine if audio operations are supported. A target responding to a PLAY
AUDIO command which has a transfer length of zero with CHECK CONDITION status
and setting the sense key to ILLEGAL REQUEST does not support audio play
operations.
The logical block address field specifies the logical block at which the
audio playback operation shall begin.
The transfer length field specifies the number of contiguous logical blocks
that shall be played. A transfer length field of zero indicates that no audio
operation shall occur. This condition shall not be considered as an error.
If the logical block length is not equal to the sector size the target may
adjust the starting logical block address and the transfer length. In such
case, it is recommended that the target start the audio play operation with
the beginning of a sector whenever the starting logical address falls within
that sector (MSF unit). If the requested transfer length causes the end of an
audio play operation to fall within a sector the target may continue the play
operation through the end of that sector.
If the starting address is not found, if the address is not within an audio
track, or if a not ready condition exists, the command shall be terminated
with CHECK CONDITION status.
If the CD-ROM information type (data vs. audio) changes the sense key shall
be set to BLANK CHECK and the additional sense code set to END OF USER AREA
ENCOUNTERED ON THIS TRACK.
If the logical block address requested is not within an audio track the
command shall be terminated with CHECK CONDITION status. The sense key shall
be set to BLANK CHECK and the additional sense code set to ILLEGAL MODE FOR
THIS TRACK.
13.2.3. PLAY AUDIO(12) Command
Table 13-7: PLAY AUDIO(12) Command
==============================================================================
Bit| 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 |
Byte | | | | | | | | |
==============================================================================
0 | Operation Code (A5h) |
-----|-----------------------------------------------------------------------|
1 | Logical Unit Number | Reserved | RelAdr |
-----|-----------------------------------------------------------------------|
2 | (MSB) |
-----|--- ---|
3 | |
-----|--- Logical Block Address ---|
4 | |
-----|--- ---|
5 | (LSB)|
-----|-----------------------------------------------------------------------|
6 | (MSB) |
-----|--- ---|
7 | |
-----|--- Transfer Length ---|
8 | |
-----|--- ---|
9 | (LSB) |
-----|-----------------------------------------------------------------------|
10 | Reserved |
-----|-----------------------------------------------------------------------|
11 | Control |
==============================================================================
The PLAY AUDIO(12) command (Table 13-7) requests the target to begin an
audio playback operation. The command function (Immed and SOTC bits) and the
output of audio signals shall be as specified by the settings of the mode
parameters (see 13.3.3.1.). See the PLAY AUDIO(10) command for a description
of the fields in this command.
13.2.4. PLAY AUDIO MSF Command
Table 13-8: PLAY AUDIO MSF Command
==============================================================================
| 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 |
Byte | | | | | | | | |
==============================================================================
0 | Operation Code (47h) |
-----|-----------------------------------------------------------------------|
1 | Logical Unit Number | Reserved |
-----|-----------------------------------------------------------------------|
2 | Reserved |
-----|-----------------------------------------------------------------------|
3 | Starting M Field |
-----|-----------------------------------------------------------------------|
4 | Starting S Field |
-----|-----------------------------------------------------------------------|
5 | Starting F Field |
-----|-----------------------------------------------------------------------|
6 | Ending M Field |
-----|-----------------------------------------------------------------------|
7 | Ending S Field |
-----|-----------------------------------------------------------------------|
8 | Ending F Field |
-----|-----------------------------------------------------------------------|
9 | Control |
==============================================================================
The PLAY AUDIO MSF command (Table 13-8) requests the target to begin an
audio playback operation. The command function (Immed and SOTC bits) and the
output of audio signals shall be as specified by the settings of the mode
parameters (see 13.3.3.1.).
The starting M field, the starting S field, and the starting F field specify
the absolute MSF address at which the audio play operation shall begin. The
ending M field, the ending S field, and the ending F field specify the
absolute MSF address at which the audio play operation shall end. All
contiguous audio sectors between the starting and the ending MSF address shall
be played.
A starting MSF address equal to an ending MSF address causes no audio play
operation to occur. This shall not be considered an error. If the starting
MSF address is less than the ending MSF address, the command shall be
terminated with CHECK CONDITION status. The sense key shall be set to ILLEGAL
REQUEST.
If the starting address is not found, or if the address is not within an
audio track, or if a not ready condition exists, the command shall be
terminated with CHECK CONDITION status. See 13.1.7 for a description of error
reporting information.
13.2.5. PLAY AUDIO TRACK INDEX Command
Table 13-9: PLAY AUDIO TRACK INDEX Command
==============================================================================
Bit| 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 |
Byte | | | | | | | | |
==============================================================================
0 | Operation Code (48h) |
-----|-----------------------------------------------------------------------|
1 | Logical Unit Number | Reserved |
-----|-----------------------------------------------------------------------|
2 | Reserved |
-----|-----------------------------------------------------------------------|
3 | Reserved |
-----|-----------------------------------------------------------------------|
4 | Starting Track |
-----|-----------------------------------------------------------------------|
5 | Starting Index |
-----|-----------------------------------------------------------------------|
6 | Reserved |
-----|-----------------------------------------------------------------------|
7 | Ending Track |
-----|-----------------------------------------------------------------------|
8 | Ending Index |
-----|-----------------------------------------------------------------------|
9 | Control |
==============================================================================
The PLAY AUDIO TRACK INDEX command (Table 13-9) requests the target to begin
an audio play operation. The command function (Immed and SOTC bits) and the
output of audio signals shall be as specified by the settings of the mode
parameters (see 13.3.3.1.).
The starting track field specifies the track number of the starting audio
track. The starting index field specifies the index number within the track
at which the audio play operation shall begin.
The ending track field specifies the track number of the ending audio track.
The ending index field specifies the index number within the track after which
the audio play operation shall stop. The audio play operation shall terminate
at the last block with an index number equal to the ending index. All
contiguous audio sectors between the starting and the ending address shall be
played.
If the starting address is less than the ending address, the command shall
be terminated with CHECK CONDITION status. The sense key shall be set to
ILLEGAL REQUEST.
If the starting address is not found, or if the address is not within an
audio track, or if a not ready condition exists, the command shall be
terminated with CHECK CONDITION status. See 13.1.7 for a description of error
reporting information.
IMPLEMENTORS NOTE: Valid values for the track and index fields are 1 to 99.
A starting index value of one specifies that playback is to start with the
first audio sector of the track following the (optional) pause. A last
index value of 99 specifies that playback continues through the last sector
of the track.
If the ending track is greater than the last information track on the media,
the playback shall continue until the last track is complete. If the ending
index is greater than the largest index value on the ending track, the
playback shall continue until this track is complete then terminate. These
conditions shall not be considered errors.
If the starting index is greater than the largest index value on the
starting track, and the stop on track crossing (SOTC) bit of the audio control
MODE SELECT parameters page (see 13.3.3.1) is zero, the playback operation
shall start at the beginning of the next track. This situation is not an
error.
If the starting index is greater than the largest index value on the
starting track, and the stop on track crossing (SOTC) bit of the audio control
MODE SELECT parameters page (see 13.3.3.1) is one, the playback shall not
begin. The target shall return CHECK CONDITION, and the sense key shall be set
to ILLEGAL REQUEST.
IMPLEMENTORS NOTE: The operation of the SOTC bit described above comes about
because the user may not be able to determine the largest index value on a
track, either from the table of contents or by other means. The SOTC bit one
case allows the user to determine the largest index. The SOTC bit zero case
allows the user to set up play operations without complete knowledge of the
media layout.
13.2.6. PLAY AUDIO TRACK RELATIVE(10) Command
Table 13-10: PLAY AUDIO TRACK RELATIVE(10) Command
==============================================================================
Bit| 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 |
Byte | | | | | | | | |
==============================================================================
0 | Operation Code (49h) |
-----|-----------------------------------------------------------------------|
1 | Logical Unit Number | Reserved |
-----|-----------------------------------------------------------------------|
2 | (MSB) |
-----|--- ---|
3 | |
-----|--- Track Relative Logical Block Address ---|
4 | |
-----|--- ---|
5 | (LSB)|
-----|-----------------------------------------------------------------------|
6 | Starting Track |
-----|-----------------------------------------------------------------------|
7 | (MSB) |
-----|--- Transfer Length ---|
8 | (LSB) |
-----|-----------------------------------------------------------------------|
9 | Control |
==============================================================================
The PLAY AUDIO TRACK RELATIVE command (Table 13-10) requests that the device
begin an audio playback operation. The starting address is specified as a
track relative logical block address within the specified starting track. The
command function (Immed and SOTC bits) and the output of audio signals shall
be as specified by the settings of the mode parameters (see 13.3.3.1.).
The starting track field specifies the track number of the starting audio
track.
The track relative logical block address (TRLBA) field specifies the two's
complement starting logical block address relative to the beginning of the
first sector on the track with an index value of one. Negative values indicate
a starting location within the audio pause area at the beginning of the
requested track.
The transfer length field specifies the number of contiguous logical blocks
that shall be output as audio data. A transfer length field of zero indicates
that no audio playback operation shall occur. This condition shall not be
considered as an error. Any other value indicates the number of logical
blocks that shall be output.
If the logical block length is not equal to the sector size the target may
adjust the starting logical block address and the transfer length. In such
case, it is recommended that the target start the audio play operation with
the beginning of a sector whenever the starting logical address falls within
that sector (MSF unit). If the requested transfer length causes the end of an
audio play operation to fall within a sector the target may continue the play
operation through the end of that sector.
If the starting address is not found, or if the address is not within an
audio track, or if a not ready condition exists, the command is terminated
with CHECK CONDITION status. See 13.1.7 for a description of error reporting
information.
13.2.7. PLAY AUDIO TRACK RELATIVE(12) Command
Table 13-11: PLAY AUDIO TRACK RELATIVE(12) Command
==============================================================================
Bit| 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 |
Byte | | | | | | | | |
==============================================================================
0 | Operation Code (A9h) |
-----|-----------------------------------------------------------------------|
1 | Logical Unit Number | Reserved |
-----|-----------------------------------------------------------------------|
2 | (MSB) |
-----|--- ---|
3 | |
-----|--- Track Relative Logical Block Address ---|
4 | |
-----|--- ---|
5 | (LSB)|
-----|-----------------------------------------------------------------------|
6 | (MSB) |
-----|--- ---|
7 | |
-----|--- Transfer Length ---|
8 | |
-----|--- ---|
9 | (LSB) |
-----|-----------------------------------------------------------------------|
10 | Starting Track |
-----|-----------------------------------------------------------------------|
11 | Control |
==============================================================================
The PLAY AUDIO TRACK RELATIVE(12) command (Table 13-11) requests that the
device begin an audio playback operation. The command function (Immed and SOTC
bits) and the output of audio signals shall be as specified by the settings of
the mode parameters (see 13.3.3.1.). See the PLAY AUDIO TRACK RELATIVE(10)
command for a description of the fields in this command.
13.2.8. READ CD-ROM CAPACITY Command
Table 13-12: READ CD-ROM CAPACITY Command
==============================================================================
Bit| 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 |
Byte | | | | | | | | |
==============================================================================
0 | Operation Code (25h) |
-----|-----------------------------------------------------------------------|
1 | Logical Unit Number | Reserved | RelAdr |
-----|-----------------------------------------------------------------------|
2 | (MSB) |
- - -|- - - -|
3 | |
- - -|- - Logical Block Address - -|
4 | |
- - -|- - - -|
5 | (LSB) |
-----|-----------------------------------------------------------------------|
6 | Reserved |
-----|-----------------------------------------------------------------------|
7 | Reserved |
-----|-----------------------------------------------------------------------|
8 | Reserved | PMI |
-----|-----------------------------------------------------------------------|
9 | Control |
==============================================================================
The READ CD-ROM CAPACITY command (Table 13-12) provides a means for the
initiator to request information regarding the capacity of the logical unit.
IMPLEMENTORS NOTE: This command has the same operation code (25h) as the
READ CAPACITY command (see 8.2.7). The general function is the same but the
exact definitions of the returned logical block address is modified to allow
returning a possibly inexact value (but one with a known error bound) based
on CD-ROM table of contents data. For many CD-ROM devices, this
implementation allows a quicker response.
A partial medium indicator (PMI) bit of zero indicates that the information
returned in the READ CD-ROM CAPACITY data shall be the logical block address
and block length (in bytes) of the last valid logical block of the logical
unit for seek operations. The logical block address returned shall be greater
than or equal to the last readable or playable block. If greater, this address
may be in a transition area beyond the last valid logical block for read or
audio play operations. The value returned shall not be not be more than 75
sectors (MSF units) greater than the logical block address of the last
readable or playable block. (This value arises because the CD-ROM Table of
Contents lead-out track location has a +/- 75 sector tolerance when the lead-
out track is encoded as an audio track.) The logical block address in the
command descriptor block shall be set to zero for this option.
A PMI bit of one indicates that the information returned shall be the
logical block address and block length (in bytes) of the last logical block
address after which a substantial delay in data transfer will be encountered.
This logical block address shall be greater than or equal to the logical block
address specified in the command descriptor block. On CD-ROM media, this is
interpreted to be the last readable or playable logical block of the
information area containing or immediately following the specified logical
block address.
IMPLEMENTORS NOTE: This option may take several seconds to complete on CD-
ROM media.
See 8.1.10 for a description of the relative address bit (RelAdr).
Eight bytes of READ CD-ROM CAPACITY data (Table 13-13) shall be sent during
the DATA IN phase of the command.
Table 13-13: READ CAPACITY Data Format
==============================================================================
Byte | Description |
==============================================================================
0 | (MSB) |
- - -|- - Logical Block Address - -|
3 | (LSB) |
-----|-----------------------------------------------------------------------|
4 | (MSB) |
- - -|- - Block Length - -|
7 | (LSB) |
==============================================================================
13.2.9. READ HEADER Command
Table 13-14: READ HEADER Command
==============================================================================
Bit| 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 |
Byte | | | | | | | | |
==============================================================================
0 | Operation Code (44h) |
-----|-----------------------------------------------------------------------|
1 | Logical Unit Number | Reserved | MSF |Reserved|
-----|-----------------------------------------------------------------------|
2 | (MSB) |
-----|--- ---|
3 | |
-----|--- Logical Block Address ---|
4 | |
-----|--- ---|
5 | (LSB) |
-----|-----------------------------------------------------------------------|
6 | Reserved |
-----|-----------------------------------------------------------------------|
7 | (MSB) |
-----|--- Allocation Length ---|
8 | (LSB) |
-----|-----------------------------------------------------------------------|
9 | Control |
==============================================================================
The READ HEADER command (Table 13-14) requests that the device return the
CD-ROM data block address header (Table 13-15) of the requested logical block.
See 13.1.5. for a description of the MSF bit.
The logical block address field specifies the logical block at which the
read header operation shall begin.
See the READ command for exception handling. If the logical block size is
other than the physical block size, it shall be mapped into the appropriate
physical block from which the data would have been read.
Table 13-15: READ HEADER Data Format
==============================================================================
Bit| 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 |
Byte | | | | | | | | |
==============================================================================
0 | CD-ROM Data Mode |
-----|-----------------------------------------------------------------------|
1 | Reserved |
-----|-----------------------------------------------------------------------|
2 | Reserved |
-----|-----------------------------------------------------------------------|
3 | Reserved |
-----|-----------------------------------------------------------------------|
4 | (MSB) |
- - -|- - - - Absolute CD-ROM Address - - - -|
7 | (LSB) |
==============================================================================
The CD-ROM data mode field specifies the CD-ROM Data Mode of the logical
blocks in this sector of data. The values in this field are defined in Table
13-16.
Table 13-16: CD-ROM Data Mode Codes
==============================================================================
CD-ROM User Data Field Contents Auxiliary Field Contents
Mode (2048 bytes) (288 bytes)
------------------------------------------------------------------------------
00h All bytes zero All bytes zero
01h User Data L-EC symbols
02h User Data User Data
03h - FFh Reserved Reserved
==============================================================================
If the MSF bit is zero, the absolute address field gives the logical block
address of the first logical block in the physical sector where the data for
the requested logical block address is found. If the MSF bit is one, the
absolute address field gives the MSF address of the sector where the data for
the requested logical block address is found. (See 13.1.5.)
13.2.10. READ SUB-CHANNEL Command
Table 13-17: READ SUB-CHANNEL Command
==============================================================================
Bit| 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 |
Byte | | | | | | | | |
==============================================================================
0 | Operation Code (42h) |
-----|-----------------------------------------------------------------------|
1 | Logical Unit Number | Reserved | MSF |Reserved|
-----|-----------------------------------------------------------------------|
2 |Reserved| SubQ | Reserved |
-----|-----------------------------------------------------------------------|
3 | Sub-channel Data Format |
-----|-----------------------------------------------------------------------|
4 | Reserved |
-----|-----------------------------------------------------------------------|
5 | Reserved |
-----|-----------------------------------------------------------------------|
6 | Track Number |
-----|-----------------------------------------------------------------------|
7 | (MSB) |
-----|--- Allocation Length ---|
8 | (LSB) |
-----|-----------------------------------------------------------------------|
9 | Control |
==============================================================================
The READ SUB-CHANNEL command (Table 13-17) requests that the target return
the requested sub-channel data plus the state of audio play operations.
IMPLEMENTORS NOTE: Sub-channel data returned by this command may be from
the last appropriate sector encountered by a current or previous media
accessing operation. When there is no current audio play operation, the
target may access the media to read the sub-channel data. The target is
responsible that the data returned are current and consistent. For example
with sub-channel data format 0, the International Standard Recording Code
(ISRC) data reported must have been read from the same track as the reported
current position data.
See 13.1.5. for a description of the MSF bit.
The Sub Q bit set to one requests the target return the Q sub-channel data.
The Sub Q bit set to zero requests that no sub-channel data be returned. This
shall not be considered an error.
NOTE: The other bits in this byte are reserved for future standardization
when they may be defined to request other sub-channel data.
The Sub-channel Data Format field specifies the returned Sub Channel Data.
If this field is 00h, Sub-Q Channel data is returned. If this field is 01h,
02h or 03h, the requested Sub-Q data item is returned.
Table 13-18: Subchannel Data Format Codes
==============================================================================
Format Code | Returned data |
----------------|------------------------------------------------------------|
00h | Sub-Q Channel data |
----------------|------------------------------------------------------------|
01h | CD-ROM Current Position |
----------------|------------------------------------------------------------|
02h | Media Catalog Number (UPC/Bar Code) |
----------------|------------------------------------------------------------|
03h | Track International-Standard-Recording-Code (ISRC) |
----------------|------------------------------------------------------------|
04h - EFh | Reserved |
----------------|------------------------------------------------------------|
F0h - FFh | Vendor Specific |
==============================================================================
The Track Number field specifies the track from which ISRC data is read.
This field must have a value between 01h and 63h (99bcd), and is valid only
when the Sub-channel Data Format field is 03h. In this case, the target
returns ISRC data for this track.
The READ SUB-CHANNEL command data formats (Tables 13-19, 13-23. 13-24, and
13-25) consist of a four-byte header followed by a sub-channel data block.
The header contains the audio status byte and the sub-channel data length
field. If the SUB-Q bit is zero, the target shall not return the sub-channel
data block, in this case the sub-channel data length is 0.
Table 13-19: Sub-Q Channel Data Format
==============================================================================
Bit| 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 |
Byte | | | | | | | | |
==============================================================================
| Sub-channel Data Header |
==============================================================================
0 | Reserved |
-----|-----------------------------------------------------------------------|
1 | Audio Status |
-----|-----------------------------------------------------------------------|
2 | (MSB) |
-----|--- Sub-channel Data Length ---|
3 | (LSB) |
==============================================================================
| Sub-Q Channel Data Block |
==============================================================================
4 | Sub Channel Data Format code (00h) |
-----|-----------------------------------------------------------------------|
5 | ADR | Control |
-----|-----------------------------------------------------------------------|
6 | Track Number |
-----|-----------------------------------------------------------------------|
7 | Index Number |
-----|-----------------------------------------------------------------------|
8 | (MSB) |
- - -|- - - - Absolute CD-ROM Address - - - -|
11 | (LSB) |
-----|-----------------------------------------------------------------------|
12 | (MSB) |
- - -|- - - - Track Relative CD-ROM Address - - - -|
15 | (LSB) |
-----|-----------------------------------------------------------------------|
16 | MCVal | Reserved |
-----|-----------------------------------------------------------------------|
17 | (MSB) |
- - -|- - - - Media Catalog Number (UPC/Bar Code) - - - -|
31 | (LSB) |
-----|-----------------------------------------------------------------------|
32 | TCVal | Reserved |
-----|-----------------------------------------------------------------------|
33 | (MSB) |
- - -|- - - - Track International-Standard-Recording-Code (ISRC) - - - -|
47 | (LSB) |
==============================================================================
The audio status field indicates the status of audio play operations. The
audio status values are defined in Table 13-20. Audio status values greater
than zero are returned only to the initiator that requested the last audio
play operation. Audio status values 13h and 14h return information on previous
audio operations; they are returned only once after the condition has
occurred. If another audio play operation is not requested, the audio status
returned for subsequent READ SUB-CHANNEL commands is 15h.
Table 13-20: Audio Status Codes
==============================================================================
Status Description |
----------|------------------------------------------------------------------|
00h | Audio status byte not supported or not valid |
----------|------------------------------------------------------------------|
11h | Audio play operation in progress. |
----------|------------------------------------------------------------------|
12h | Audio play operation paused. |
----------|------------------------------------------------------------------|
13h | Audio play operation successfully completed. |
----------|------------------------------------------------------------------|
14h | Audio play operation stopped due to error. |
----------|------------------------------------------------------------------|
15h | No current audio status to return |
==============================================================================
The Sub-Channel data length specifies the length in bytes of the following
sub-channel data block. A sub-channel data length of zero indicates that no
sub-channel data block is included in the returned data.
IMPLEMENTORS NOTE: Usual values for Sub-channel data length are 0, 12, 20,
28 and 44 bytes. Sub-channel data length does not include the Sub Channel
Header.
The Sub-Q Channel data block consists of control data (bytes 4-5), current
position data (bytes 6 - 15) and identification data (bytes 16 - 47). The
control data and current position data is obtained from the Q sub-channel
information of the current block. Identification data may be reported that was
obtained from a previous block. If identification data is reported, the data
shall be valid for the sector addressed by the current position data.
(1) If an audio play operation is proceeding in the background, position
data for the last sector played shall be reported.
(2) In other cases, for instance after a READ command, the target may
either report position data for the last sector processed for that operation
or may report position data from the sector at the current read head position.
IMPLEMENTORS NOTE: When the type of information encoded in the Q sub-channel
of the current sector is the media catalog number or ISRC; the track, index,
and address fields should be extrapolated from the previous sector.
The ADR field gives the type of information encoded in the Q sub-channel of
this block, as shown in Table 13-21.
Table 13-21: ADR Sub-channel Q Field
==============================================================================
ADR Code Description
------------------------------------------------------------------------------
0h Sub-channel Q mode information not supplied.
1h Sub-channel Q encodes current position data.
(i.e. track, index, absolute address, relative address.)
2h Sub-channel Q encodes media catalog number.
3h Sub-channel Q encodes ISRC.
4h - Fh Reserved
==============================================================================
The control bits are defined in Table 13-22.
Table 13-22: Sub-channel Q Control Bits
==============================================================================
Bit equals zero equals one
------------------------------------------------------------------------------
0 Audio without pre-emphasis Audio with pre-emphasis
1 Digital copy prohibited Digital copy permitted
2 Audio track Data track
3 Two channel audio Four channel audio
==============================================================================
The track number specifies the current track number.
The index number specifies the index number in the current track.
The absolute CD-ROM address field gives the current location relative to the
logical beginning of the media. If the MSF bit is zero, this field is a
logical block address. If the MSF bit is one, this field is an absolute MSF
address. (See 13.1.5.)
The track relative CD-ROM address field gives the current location relative
to the logical beginning of the current track. If the MSF bit is zero, this
field is a track relative logical block address. (If the current block is in
the pre-gap area of a track, this will be a negative value, expressed as a
twos complement number. See 13.1.5). If the MSF bit is one, this field is the
relative MSF address from the Q sub-channel.
A media catalog valid (MCVal) bit of one indicates that the media catalog
number field is valid. A MCVal bit of zero indicates that the media catalog
number field is not valid.
The media catalog number field contains the identifying number of this media
according to the uniform product code values (UPC/EAN Bar Coding) expressed in
ASCII. Non-zero values in this field are controlled by the Uniform Product
Code Council and the European Article Number Council (see Section 2). A value
in this field of all ASCII zeros indicates that the media catalog number is
not supplied.
The track code valid (TCVal) bit of one indicates that the track ISRC field
is valid. A TCVal bit of zero indicates that the track International-
Standard-Recording-Code (ISRC) field is not valid.
The track ISRC field contains the identifying number of this media according
to the ISRC standards (DIN-31-621) expressed in ASCII.
Table 13-23: CD-ROM Current Position Data Format
==============================================================================
Bit| 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 |
Byte | | | | | | | | |
==============================================================================
| Sub-channel Data Header |
==============================================================================
0 | Reserved |
-----|-----------------------------------------------------------------------|
1 | Audio Status |
-----|-----------------------------------------------------------------------|
2 | (MSB) |
-----|--- Sub-Channel Data Length ---|
3 | (LSB) |
==============================================================================
| CD-ROM Current Position Data Block |
==============================================================================
4 | Sub Channel Data Format code (01h) |
-----|-----------------------------------------------------------------------|
5 | ADR | Control |
-----|-----------------------------------------------------------------------|
6 | Track Number |
-----|-----------------------------------------------------------------------|
7 | Index Number |
-----|-----------------------------------------------------------------------|
8 | (MSB) |
- - -|- - - - Absolute CD-ROM Address - - - -|
11 | (LSB) |
-----|-----------------------------------------------------------------------|
12 | (MSB) |
- - -|- - - - Track Relative CD-ROM Address - - - -|
15 | (LSB) |
==============================================================================
Table 13-24: Media Catalog Number Data Format
==============================================================================
Bit| 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 |
Byte | | | | | | | | |
==============================================================================
| Sub-channel Data Header |
==============================================================================
0 | Reserved |
-----|-----------------------------------------------------------------------|
1 | Audio Status |
-----|-----------------------------------------------------------------------|
2 | (MSB) |
-----|--- Sub-Channel Data Length ---|
3 | (LSB) |
==============================================================================
| Media Catalog Number Data Block |
==============================================================================
4 | Sub Channel Data Format code (02h) |
------------------------------------------------------------------------------
5 | Reserved |
------------------------------------------------------------------------------
6 | Reserved |
------------------------------------------------------------------------------
7 | Reserved |
------------------------------------------------------------------------------
8 | MCVal | Reserved |
-----|-----------------------------------------------------------------------|
9 | (MSB) |
- - -|- - - - Media Catalog Number (UPC/Bar Code) - - - -|
23 | (LSB) |
==============================================================================
If Media Catalog Number data is found, the MCVal bit is set to one. If MCN
data is not detected, the MCVal bit is set to zero to indicate the Media
Catalog Number field is invalid.
IMPLEMENTORS NOTE: Media Catalog Number data returned by this command with
Sub-channel Data Format field code 02h may be from any block which has
UPC/Bar Code Q sub-channel data. (This code is constant anywhere in every
applicable disc.)
Table 13-25: Track International Standard Recording Code Data Format
==============================================================================
Bit| 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 |
Byte | | | | | | | | |
==============================================================================
| Sub-channel Data Header |
==============================================================================
0 | Reserved |
-----|-----------------------------------------------------------------------|
1 | Audio Status |
-----|-----------------------------------------------------------------------|
2 | (MSB) |
-----|--- Sub-Channel Data Length ---|
3 | (LSB) |
==============================================================================
| Track ISRC Data Block |
==============================================================================
4 | Sub Channel Data Format code (03h) |
------------------------------------------------------------------------------
5 | ADR | Control |
------------------------------------------------------------------------------
6 | Track Number |
------------------------------------------------------------------------------
7 | Reserved |
------------------------------------------------------------------------------
8 | TCVal | Reserved |
-----|-----------------------------------------------------------------------|
9 | (MSB) |
- - -|- - - - Track International-Standard-Recording-Code (ISRC) - - - -|
23 | (LSB) |
==============================================================================
If ISRC data is detected, the TCVal bit is set to one. If ISRC data is not
detected, the TCVal bit is set to zero to indicate the ISRC field is invalid.
IMPLEMENTORS NOTE: Track ISRC data returned by this command with Sub-
Channel Data Format field 03h may be from any block in the specified track
which has ISRC data.
13.2.11. READ TOC Command
Table 13-26: READ TOC Command
==============================================================================
Bit| 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 |
Byte | | | | | | | | |
==============================================================================
0 | Operation Code (43h) |
-----|-----------------------------------------------------------------------|
1 | Logical Unit Number | Reserved | MSF |Reserved|
-----|-----------------------------------------------------------------------|
2 | Reserved |
-----|-----------------------------------------------------------------------|
3 | Reserved |
-----|-----------------------------------------------------------------------|
4 | Reserved |
-----|-----------------------------------------------------------------------|
5 | Reserved |
-----|-----------------------------------------------------------------------|
6 | Starting Track |
-----|-----------------------------------------------------------------------|
7 | (MSB) |
-----|--- Allocation Length ---|
8 | (LSB) |
-----|-----------------------------------------------------------------------|
9 | Control |
==============================================================================
The READ TOC command (Table 13-26) requests the target transfers data from
the table of contents to the initiator. The format of the data returned is
specified in Table 13-27.
See 13.1.5. for a description of the MSF bit.
The starting track field specifies the starting track number for which the
data shall be returned. If this value is zero, the table of contents data
shall begin with the first track on the medium. The data is returned in
contiguous ascending track number order.
If the starting track field is not valid for the currently installed medium,
the command shall be terminated with CHECK CONDITION status. The sense key
shall be set to ILLEGAL REQUEST and the additional sense code set to INVALID
FIELD IN CDB.
IMPLEMENTORS NOTE: The maximum TOC data length possible on currently
available CD-ROM media is 804 bytes, or 100 TOC track descriptors.
Table 13-27: READ TOC Data Format
==============================================================================
Bit| 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 |
Byte | | | | | | | | |
==============================================================================
0 | (MSB) |
-----|--- TOC Data Length ---|
1 | (LSB) |
-----|-----------------------------------------------------------------------|
2 | First Track Number |
-----|-----------------------------------------------------------------------|
3 | Last Track Number |
==============================================================================
| TOC Track Descriptor(s) |
==============================================================================
0 | Reserved |
-----|-----------------------------------------------------------------------|
1 | ADR | Control |
-----|-----------------------------------------------------------------------|
2 | Track Number |
-----|-----------------------------------------------------------------------|
3 | Reserved |
-----|-----------------------------------------------------------------------|
4 | (MSB) |
- - -|- - - - Absolute CD-ROM Address - - - -|
7 | (LSB) |
==============================================================================
The TOC data block contains a four byte header followed by zero or more TOC
track descriptors.
The TOC data length specifies the length in bytes of the following TOC data
that is available to be transferred during the DATA IN phase. The TOC data
length value does not include the TOC data length field itself.
The first track number field indicates the first track number in the table
of contents.
The last track number field indicates the last track number in the table of
contents before the lead-out track number.
IMPLEMENTORS NOTE: The first track number is not required to be one. A
disc may start at any valid track number. The track numbers between the
first track number and the last track number are required to be in
contiguous ascending order, except for the lead-out track.
The ADR field gives the type of information encoded in the Q Sub-channel of
the block where this TOC entry was found. The possible ADR values are defined
in Table 13-21.
The control field indicates the attributes of the track. The possible
control field values are defined in Table 13-22.
The track number field indicates the track number for which the data in the
TOC track descriptor is valid. A track number of 0AAh indicates the track
descriptor is for the start of the lead-out area.
The absolute CD-ROM address contains the address of the first block with
user information for that track number as read from the table of contents. An
MSF bit of zero indicates that the absolute CD-ROM address field contains a
logical block address. An MSF bit of one indicates the absolute CD-ROM
address field contains an MSF address (see 13.1.5).
IMPLEMENTORS NOTE: The starting logical block address value recovered from
the TOC has a tolerance of zero for data tracks and plus or minus 75 CD
sectors for audio tracks. This tolerance is multiplied by a factor
dependent on the logical block Length.
13.3. Parameters for CD-ROM Devices
13.3.1. Diagnostic Parameters
This section defines the descriptors and pages for diagnostic parameters
used with CD-ROM devices.
The diagnostic page codes for CD-ROM devices are defined in Table 13-28.
Table 13-28: Diagnostic Page Codes
==============================================================================
Page Code Description Section
------------------------------------------------------------------------------
00h Supported Diagnostic Pages 7.3.1.1
01h - 3Fh Reserved (for all device type pages)
40h - 7Fh Reserved
80h - FFh Vendor-specific pages
==============================================================================
13.3.2. Log Parameters
This section defines the descriptors and pages for log parameters used with
CD-ROM devices.
The log page codes for CD-ROM devices are defined in Table 13-29.
Table 13-29: Log Page Codes
==============================================================================
Page Code Description Section
------------------------------------------------------------------------------
01h Buffer Over-Run/Under-Run Page 7.3.2.1
03h Error Counter Page (Read) Page 7.3.2.2
07h Last n Error Events Page 7.3.2.3
06h Non-Medium Error Page 7.3.2.4
02h, 04h, 05h, 08h - 2Fh, 3Fh Reserved
00h Supported Log Pages 7.3.2.5
30h - 3Eh Vendor-specific pages
==============================================================================
13.3.3. Mode Parameters
This section defines the descriptors and pages for mode parameters used with
CD-ROM devices.
The mode parameter list, including the mode parameter header and mode block
descriptor are defined in 7.3.3.
The medium-type code field is contained in the mode parameter header (see
Table 7-61 and 7-62). Table 13-30 defines the medium type values for CD-ROM
devices.
Table 13-30: CD-ROM Medium Type Codes
===================================================
Code Value Medium Type
------------ -------------------------------------
00h Default (only one type supported)
01h 120 mm CD-ROM data only
02h 120 mm CD-DA audio only
03h 120 mm CD-ROM data and audio combined
04h Reserved
05h 80 mm CD-ROM data only
06h 80 mm CD-DA audio only
07h 80 mm CD-ROM data and audio combined
08h - 7Fh Reserved
80h - FFh Vendor unique
===================================================
The device specific parameter field is contained in the mode parameter
header (see Table 7-61, (byte 2) and 7-62 (byte 3)). Table 13-31 defines the
device specific parameter field for CD-ROM devices.
Table 13-31: CD-ROM Device Specific Parameter
==============================================================================
Bit| 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 |
Byte | | | | | | | | |
==============================================================================
| Reserved | Cache | Reserved | EBC |
==============================================================================
When used with the MODE SELECT command the cache bit is reserved.
When used with a MODE SENSE command, a cache bit of zero indicates that the
target does not contain a cache memory. A cache bit of one indicates that the
target contains a cache memory and supports the cache control bits (see
8.2.6).
The enable blank check (EBC) bit is reserved.
The density code field is contained in the mode parameter block descriptor
(see Table 7-63). Table 13-32 defines the density code values for CD-ROM
devices.
Table 13-32: CD-ROM Density Codes
===============================================================
Code Value Data types to be transferred
------------ -------------------------------------------------
00h Default density code
01h User Data Only
- 2048 Bytes per physical sector
02h User Data plus Auxiliary Data field
- 2336 bytes per sector
03h 4 Byte Tag Field, User Data plus Auxiliary Data
- 2340 bytes per sector
04h Audio Information Only
- (1/75th of a second per logical block)
05h - 7Fh Reserved
80h - FFh Vendor specific
===============================================================
IMPLEMENTORS NOTE: The number of bytes per sector specified by this
parameter is used with the block Length to map CD-ROM sectors to logical
block addresses.
The mode page codes for CD-ROM devices are defined in Table 13-33.
Table 13-33: Mode Page Codes
==============================================================================
Page Code Description Section
------------------------------------------------------------------------------
08h Caching Page 8.3.3.1
0Eh CD-ROM Audio Control Page 13.3.3.1
0Dh CD-ROM Page 13.3.3.2
0Ah Control Mode Page 7.3.3.1
02h Disconnect-Reconnect Page 7.3.3.2
0Bh Medium Types Supported Page 8.3.3.4
09h Peripheral Device Page 7.3.3.3
01h Read Error Recovery Page 13.3.3.3
03h - 06h, 0Ch, 0Fh - 1Fh Reserved
3Fh Returns all pages (valid only for the MODE SENSE command)
20h - 3Eh Vendor Specific (page format required)
07h Verify Error Recovery Page 13.3.3.4
==============================================================================
13.3.3.1. CD-ROM Audio Control Parameters
Table 13-34: CD-ROM Audio Control Parameters Page
==============================================================================
Bit| 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 |
Byte | | | | | | | | |
==============================================================================
0 | PS |Reserved| Page Code (0Eh) |
-----|-----------------------------------------------------------------------|
1 | Parameter Length (0Eh) |
-----|-----------------------------------------------------------------------|
2 | Reserved | Immed | SOTC |Reserved|
-----|-----------------------------------------------------------------------|
3 | Reserved |
-----|-----------------------------------------------------------------------|
4 | Reserved |
-----|-----------------------------------------------------------------------|
5 | APRVal | Reserved | Format of LBAs / Sec. |
-----|-----------------------------------------------------------------------|
6 | (MSB) |
-----|--- Logical Blocks per Second of Audio Playback ---|
7 | (LSB)|
-----|-----------------------------------------------------------------------|
8 | Reserved | Output Port 0 Channel Selection |
-----|-----------------------------------------------------------------------|
9 | Output Port 0 Volume |
-----|-----------------------------------------------------------------------|
10 | Reserved | Output Port 1 Channel Selection |
-----|-----------------------------------------------------------------------|
11 | Output Port 1 Volume |
-----|-----------------------------------------------------------------------|
12 | Reserved | Output Port 2 Channel Selection |
-----|-----------------------------------------------------------------------|
13 | Output Port 2 Volume |
-----|-----------------------------------------------------------------------|
14 | Reserved | Output Port 3 Channel Selection |
-----|-----------------------------------------------------------------------|
15 | Output Port 3 Volume |
==============================================================================
The CD-ROM audio control parameters page (Table 13-34) sets the playback
modes and output controls for subsequent PLAY AUDIO commands and any current
audio playback operation.
The parameters savable (PS) bit is only used with the MODE SENSE command.
This bit is reserved with the MODE SELECT command. A PS bit of one indicates
that the target is capable of saving the page in a non-volatile vendor-
specific location.
An immediate (Immed) bit of zero indicates the target shall not send
completion status until the audio playback operation is terminated.
An Immed bit of one indicates the target shall send completion status as
soon as the playback operation has been started.
IMPLEMENTORS NOTE: It is recommended that a Logical Unit type RESERVE be
issued prior to starting audio play operations with an Immed bit of one in
any multiple initiator environment.
A stop on track crossing (SOTC) bit of zero indicates the target shall
terminate the audio playback operation when the transfer length is satisfied.
Multiple tracks shall be played as necessary. Periods of time encoded as
audio pause/silence at the beginning of tracks, (index 0,) shall also be
played.
A stop on track crossing (SOTC) bit of one indicates the target shall
terminate the audio playback operation when the beginning of a following track
is encountered.
The audio playback rate valid (APRVal) bit value of one indicates that the
format of logical blocks per second field and the logical blocks per second of
audio playback field are valid.
The format of logical blocks addresses per second field gives the multiplier
to be used with the logical blocks per second of audio playback, as defined in
the following table:
===================================================================
Format of LBAs / Sec value Multiplier for LBAs / Sec field
------------------------------ ----------------------------------
0h 1
1h - 7h Reserved
8h 1/256
9h - Fh Reserved
===================================================================
IMPLEMENTORS NOTE: This field is provided as a means to return fractional
(i.e., non-integral) values in the logical block addresses per second of
audio playback. This shall occur when logical block sizes that are not even
multiples or divisions of the physical block size are used.
The logical blocks per Second of Audio Playback field gives the relationship
between time and the duration of play per logical block address. The value in
this field is to be multiplied by the value in Format of LBAs per Second
field.
IMPLEMENTORS NOTE: The logical blocks per second of audio playback field and
its companion format of LBAs per second field may not be supported by most
current CD-ROM devices as a modifiable mode select parameter.
The output port channel selection specifies the audio channels from the disc
to which this output port should be connected. See Table 13-35. More than
one output port may be connected to an audio channel. More than one audio
channel may be connected to an output port.
Table 13-35: Output Port Channel Selection
=================================================
0000 output port muted
0001 connect audio channel 0 to this output port
0010 connect audio channel 1 to this output port
0100 connect audio channel 2 to this output port
1000 connect audio channel 3 to this output port
=================================================
The channel volume control indicates the relative volume level for this
audio output port. A value of zero indicates the output is muted, a value of
FFh indicates maximum volume level.
IMPLEMENTORS NOTE: If volume controls are implemented, the default volume
level should be no more than 25% of the maximum level as a personal safety
consideration.
13.3.3.2. CD-ROM Device Parameters
Table 13-36: CD-ROM Parameters Page
==============================================================================
Bit| 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 |
Byte | | | | | | | | |
==============================================================================
0 | PS |Reserved| Page Code (0Dh) |
-----|-----------------------------------------------------------------------|
1 | Parameter Length (06h) |
-----|-----------------------------------------------------------------------|
2 | Reserved |
-----|-----------------------------------------------------------------------|
3 | Reserved | Inactivity Timer Multiplier |
-----|-----------------------------------------------------------------------|
4 | |
-----| - - - Number of MSF - S Units per MSF - M Unit - - - |
5 | |
-----|-----------------------------------------------------------------------|
6 | |
-----| - - - Number of MSF - F Units per MSF - S Unit - - - |
7 | |
==============================================================================
The CD-ROM parameters page (Table 13-36) specifies parameters that affect
all CD-ROM data types.
The parameters savable (PS) bit is only used with the MODE SENSE command.
This bit is reserved with the MODE SELECT command. A PS bit of one indicates
that the target is capable of saving the page in a non-volatile vendor-
specific location.
The inactivity timer multiplier specifies the length of time that the drive
shall remain in the hold track state after completion of a seek or read
operation (see Table 13-37).
IMPLEMENTORS NOTE: Higher values in this parameter may have an adverse
effect on the drive MTBF, in some implementations.
Table 13-37: Inactivity Timer Multiplier Values
=============================================================================
Inactivity Timer Minimum Time in Inactivity Timer Minimum Time in
Multiplier Hold Track State Multiplier Hold Track State
---------------- ---------------- ---------------- ----------------
0h Vendor specific 8h 16 Seconds
1h 125 milliseconds 9h 32 Seconds
2h 250 milliseconds Ah 1 Minute
3h 500 milliseconds Bh 2 Minutes
4h 1 Second Ch 4 Minutes
5h 2 Seconds Dh 8 Minutes
6h 4 Seconds Eh 16 Minutes
7h 8 Seconds Fh 32 Minutes
=============================================================================
The number of S Units per M Unit field gives the ratio of these MSF address
values. For media conforming to the CD-ROM and CD-DA standard, this value is
60.
The number of F Units per S Unit field gives the ratio of these MSF address
values. For media conforming to the CD-ROM and CD-DA standard, this value is
75.
13.3.3.3. Read Error Recovery Parameters
Table 13-38: Read Error Recovery Parameters Page
==============================================================================
Bit| 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 |
Byte | | | | | | | | |
==============================================================================
0 | PS |Reserved| Page Code (01h) |
-----|-----------------------------------------------------------------------|
1 | Parameter Length (06h) |
-----|-----------------------------------------------------------------------|
2 | Error Recovery Parameter |
-----|-----------------------------------------------------------------------|
3 | Read Retry Count |
-----|-----------------------------------------------------------------------|
4 | Reserved |
-----|-----------------------------------------------------------------------|
5 | Reserved |
-----|-----------------------------------------------------------------------|
6 | Reserved |
-----|-----------------------------------------------------------------------|
7 | Reserved |
==============================================================================
The read error recovery parameters page (Table 13-38) specifies the error
recovery parameters the target shall use during any command that performs a
data read operation to the media (e.g., READ, READ TOC, etc.).
The parameters savable (PS) bit is only used with the MODE SENSE command.
This bit is reserved with the MODE SELECT command. A PS bit of one indicates
that the target is capable of saving the page in a non-volatile vendor-
specific location.
The Error Recovery Parameter bits are defined in 8.3.3.6.
IMPLEMENTORS NOTE: The implementation of error recovery procedures for CD-
ROM devices is markedly different from those used for magnetic medium disk
drives. At least one level of error correction (i.e. CIRC) is required to
transfer the data stream. Therefore the performance of the drive may differ
substantially from what would be expected by sending the same error recovery
parameters to a magnetic medium device.
The correlation of the error recovery parameter and the bit settings defined
for CD-ROM devices is given in Table 13-39. The interpretation of these bit
settings for CD-ROM devices is given in Tables 13-40 through 13-45. If the
error recovery parameter is set to any other value, the command shall be
terminated with CHECK CONDITION status. The sense key shall be set to ILLEGAL
REQUEST and the additional sense code set to INVALID FIELD IN PARAMETER LIST.
The read retry count field specifies the number of times that the controller
shall attempt its read recovery algorithm.
Table 13-39: Error Recovery Parameter Bit Settings
==============================================================================
Bit| 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 |
Byte | | | | | | | | |
2 | | | TB | RC | | PER | DTE | DCR |
Value| | | | | | | | |
==============================================================================
00 | 0 0 0 0 0 |
-----+--------+--------+--------+--------+--------+--------+--------+--------|
01 | 0 0 0 0 1 |
-----+--------+--------+--------+--------+--------+--------+--------+--------|
04 | 0 0 1 0 0 |
-----+--------+--------+--------+--------+--------+--------+--------+--------|
05 | 0 0 1 0 1 |
-----+--------+--------+--------+--------+--------+--------+--------+--------|
06 | 0 0 1 1 0 |
-----+--------+--------+--------+--------+--------+--------+--------+--------|
07 | 0 0 1 1 1 |
-----+--------+--------+--------+--------+--------+--------+--------+--------|
10 | 0 1 0 0 0 |
-----+--------+--------+--------+--------+--------+--------+--------+--------|
11 | 0 1 0 0 1 |
-----+--------+--------+--------+--------+--------+--------+--------+--------|
14 | 0 1 1 0 0 |
-----+--------+--------+--------+--------+--------+--------+--------+--------|
15 | 0 1 1 0 1 |
-----+--------+--------+--------+--------+--------+--------+--------+--------|
20 | 1 0 0 0 0 |
-----+--------+--------+--------+--------+--------+--------+--------+--------|
21 | 1 0 0 0 1 |
-----+--------+--------+--------+--------+--------+--------+--------+--------|
24 | 1 0 1 0 0 |
-----+--------+--------+--------+--------+--------+--------+--------+--------|
25 | 1 0 1 0 1 |
-----+--------+--------+--------+--------+--------+--------+--------+--------|
26 | 1 0 1 1 0 |
-----+--------+--------+--------+--------+--------+--------+--------+--------|
27 | 1 0 1 1 1 |
-----+--------+--------+--------+--------+--------+--------+--------+--------|
30 | 1 1 0 0 0 |
-----+--------+--------+--------+--------+--------+--------+--------+--------|
31 | 1 1 0 0 1 |
-----+--------+--------+--------+--------+--------+--------+--------+--------|
34 | 1 1 1 0 0 |
-----+--------+--------+--------+--------+--------+--------+--------+--------|
35 | 1 1 1 0 1 |
==============================================================================
NOTE: Reserved bits are not shown and shall be zero.
A CIRC recovered data error is defined as a block for which the CIRC based
error correction algorithm was unsuccessful for a read attempt, but on a
subsequent read operation no error was reported. The number of subsequent read
operations is limited to the read retry count. Layered error correction was
not used.
A CIRC unrecovered data error is defined as a block for which the CIRC based
error correction algorithm was unsuccessful on all read attempts up to the
read retry count. Layered error correction was not used.
An L-EC recovered data error is defined as a block for which the CIRC based
error correction algorithm was unsuccessful but the layered error correction
was able to correct the block within the read retry count.
An L-EC uncorrectable data error is defined as a block which could not be
corrected by layered error correction within the read retry count.
Table 13-40: CD-ROM Error Recovery Parameters 00h - 04h
==============================================================================
Error Recovery Description
------------------------------------------------------------------------------
00h The maximum error recovery procedures available are used. If an error
occurs which is uncorrectable with the error correction codes (ECC) on
the media, data transfer is terminated with CHECK CONDITION status. The
block with the error is not transferred. The sense key is set to MEDIUM
ERROR. The information bytes give the address of the block where the
unrecovered error was detected. Recovered errors are not reported.
01h Only retries of the read operation and CIRC are used (layered error
correction is not used). Only CIRC unrecovered data errors are reported.
If an CIRC unrecovered data error occurs, data transfer is terminated
with CHECK CONDITION status. The block with the error is not
transferred. The sense key is set to MEDIUM ERROR. The information bytes
give the address of the block where the unrecovered error was detected.
Recovered errors are not reported.
04h The maximum error recovery procedures available are used. Recovered data
errors are reported. If a recovered data error occurs, data transfer is
not terminated. However, when the data transfer has completed CHECK
CONDITION status is reported. The sense key is set to RECOVERED ERROR.
The information bytes give the address of the last block where a
recovered data error was detected.
If a data error occurs which is uncorrectable with the ECC information
available on the media, data transfer is terminated and CHECK CONDITION
status is reported. The block with the error is not transferred. The
sense key is set to MEDIUM ERROR. The information bytes give the address
of the block where the uncorrectable error was detected.
=============================================================================
Table 13-41: CD-ROM Error Recovery Procedures 05h - 07h
==============================================================================
Error Recovery Description
------------------------------------------------------------------------------
05h Only retries of the read operation and CIRC are used (layered error
correction is not used). Recovered data errors are reported. If a
recovered data error occurs, data transfer is not terminated. However,
when the data transfer has completed CHECK CONDITION status is reported.
The sense key is set to RECOVERED ERROR. The information bytes give the
address of the last block where a CIRC recovered data error was detected.
If an unrecovered data error occurs data transfer is terminated and CHECK
CONDITION status is reported. The block with the error is not
transferred. The sense key is set to MEDIUM ERROR. The information bytes
give the address of the block where the unrecovered error was detected.
06h The maximum error recovery procedures are used. Recovered data errors are
reported. If a recovered data error occurs data transfer is terminated
and CHECK CONDITION status is reported. The block with the recovered
error is not transferred. The sense key is set to RECOVERED ERROR. The
information bytes give the address of the block where the recovered data
error was detected.
If a data error occurs which is uncorrectable with the ECC information on
the medium, data transfer is terminated with CHECK CONDITION status. The
block with the error is not transferred. The sense key is set to MEDIUM
ERROR. The information bytes give the address of the block where the
uncorrectable error was detected.
07h Only retries of the read operation are used (layer error correction is
not used). CIRC recovered data errors are reported. If a CIRC recovered
data error occurs, data transfer is terminated with CHECK CONDITION
status. The block with the recovered error is not transferred. The sense
key is set to RECOVERED ERROR. The information bytes give the address of
the block where the recovered data error was detected.
If an CIRC unrecovered data error occurs, data transfer is terminated
with CHECK CONDITION status. The block with the error is not transferred.
The sense key is set to MEDIUM ERROR. The information bytes give the
address of the block where the unrecovered error was detected.
=============================================================================
Table 13-42: CD-ROM Error Recovery Procedures 10h - 15h
==============================================================================
Error Recovery Description
------------------------------------------------------------------------------
10h If data transfer can be maintained, the maximum error recovery procedures
available are used. (RC = 1.) If an error occurs which is uncorrectable
with the error correction codes (ECC) on the media, or is uncorrectable
in time to maintain data transfer, the data transfer is not terminated.
However, when the data transfer has completed CHECK CONDITION status is
reported. The sense key is set to MEDIUM ERROR. The information bytes
give the address of the block where the first unrecovered error was
detected. Recovered errors are not reported.
11h If data transfer can be maintained, retries of the read operation and
CIRC are used (layered error correction is not used). (RC = 1.) Only CIRC
unrecovered data errors are reported. If an CIRC unrecovered data error
occurs, data transfer is not terminated. However, when the data transfer
has completed CHECK CONDITION status is reported. The sense key is set
to MEDIUM ERROR. The information bytes give the address of the block
where the first unrecovered error was detected. Recovered errors are not
reported.
14h If data transfer can be maintained, the maximum error recovery procedures
available are used. (RC = 1.) Recovered data errors are reported. If a
recovered data error occurs, data transfer is not terminated. However,
when the data transfer has completed CHECK CONDITION status is reported.
The sense key is set to RECOVERED ERROR. The information bytes give the
address of the block where a recovered data error was detected.
If an data error occurs which is uncorrectable with the ECC information
available on the media, or is uncorrectable in time to maintain data
transfer, the data transfer is not terminated. However, when the data
transfer has completed CHECK CONDITION status is reported. The sense key
is set to MEDIUM ERROR. The information bytes give the address of the
block where the first uncorrectable error was detected. Reporting
unrecovered errors takes precedence over reporting recovered errors.
15h If data transfer can be maintained, retries of the read operation and
CIRC are used (layered error correction is not used). (RC = 1.)
Recovered data errors are reported. If a recovered data error occurs,
data transfer is not terminated. However, when the data transfer has
completed CHECK CONDITION status is reported. The sense key is set to
RECOVERED ERROR. The information bytes give the address of the block
where a CIRC recovered data error was detected.
If an unrecovered data error occurs, data transfer is not terminated.
However, when the data transfer has completed CHECK CONDITION status is
reported. The sense key is set to MEDIUM ERROR. The information bytes
give the address of the block where the first unrecovered error was
detected. Reporting unrecovered errors takes precedence over reporting
recovered errors.
=============================================================================
Table 13-43: CD-ROM Error Recovery Procedures 20h - 24h
==============================================================================
Error Recovery Description
------------------------------------------------------------------------------
20h The maximum error recovery procedures available are used. If an error
occurs which is uncorrectable with the error correction codes (ECC) on
the media, data transfer is terminated with CHECK CONDITION status. The
block with the error is transferred. The sense key is set to MEDIUM
ERROR. The information bytes give the address of the block where the
unrecovered error was detected. Recovered errors are not reported.
21h Only retries of the read operation and CIRC are used (layered error
correction is not used). Only CIRC unrecovered data errors are reported.
If an CIRC unrecovered data error occurs data transfer is terminated with
CHECK CONDITION status. The block with the error is transferred. The
sense key is set to MEDIUM ERROR. The information bytes give the address
of the block where the unrecovered error was detected. Recovered errors
are not reported.
24h The maximum error recovery procedures available are used. Recovered data
errors are reported. If a recovered data error occurs data transfer is
not terminated. However, when the data transfer has completed CHECK
CONDITION status is reported. The sense key is set to RECOVERED ERROR.
The information bytes give the address of the last block where a
recovered data error was detected.
If a data error occurs which is uncorrectable with the ECC information
available on the media data transfer is terminated and CHECK CONDITION
status is reported. The block with the error is transferred. The sense
key is set to MEDIUM ERROR. The information bytes give the address of the
block where the uncorrectable error was detected.
==============================================================================
Table 13-44: CD-ROM Error Recovery Procedures 25h - 27h
==============================================================================
Error Recovery Description
------------------------------------------------------------------------------
25h Only retries of the read operation and CIRC are used (layered error
correction is not used). Recovered data errors are reported. If a
recovered data error occurs, data transfer is not terminated. However,
when the data transfer has completed CHECK CONDITION status is reported.
The sense key is set to RECOVERED ERROR. The information bytes give the
address of the last block where an CIRC recovered data error was
detected.
If an unrecovered data error occurs, data transfer is terminated and
CHECK CONDITION status is reported. The block with the error is
transferred. The sense key is set to MEDIUM ERROR. The information bytes
give the address of the block where the unrecovered error was detected.
26h The maximum error recovery procedures are used. Recovered data errors are
reported. If a recovered data error occurs, data transfer is terminated
and CHECK CONDITION status is reported. The block with the recovered
error is transferred. The sense key is set to RECOVERED ERROR. The
information bytes give the address of the block where the recovered data
error was detected.
If a data error occurs which is uncorrectable with the ECC information on
the media, data transfer is terminated with CHECK CONDITION status. The
block with the error is transferred. The sense key is set to MEDIUM
ERROR. The information bytes give the address of the block where the
uncorrectable error was detected.
27h Only retries of the read operation are used (layer error correction is
not used). CIRC recovered data errors are reported. If a CIRC recovered
data error occurs, data transfer is terminated with CHECK CONDITION
status. The block with the recovered error is transferred. The sense key
is set to RECOVERED ERROR. The information bytes give the address of the
block where the recovered data error was detected.
If an CIRC unrecovered data error occurs, data transfer is terminated
with CHECK CONDITION status. The block with the error is transferred. The
sense key is set to MEDIUM ERROR. The information bytes give the address
of the block where the unrecovered error was detected.
==============================================================================
Table 13-45: CD-ROM Error Recovery Procedures 30h - 35h
==============================================================================
Error Recovery Description
------------------------------------------------------------------------------
30h Same as code 10H.
31h Same as code 11H.
34h Same as code 14H.
35h Same as code 15H.
=============================================================================
13.3.3.4. Verify Error Recovery Parameters
Table 13-46: Verify Error Recovery Parameters Page
==============================================================================
Bit| 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 |
Byte | | | | | | | | |
==============================================================================
0 | PS |Reserved| Page Code (07h) |
-----|-----------------------------------------------------------------------|
1 | Parameter Length (06h) |
-----|-----------------------------------------------------------------------|
2 | Error Recovery Parameter |
-----|-----------------------------------------------------------------------|
3 | Verify Retry Count |
-----|-----------------------------------------------------------------------|
4 | Reserved |
-----|-----------------------------------------------------------------------|
5 | Reserved |
-----|-----------------------------------------------------------------------|
6 | Reserved |
-----|-----------------------------------------------------------------------|
7 | Reserved |
==============================================================================
The verify error recovery parameters page (Table 13-46) specifies the error
recovery parameter the target shall use during verify operations.
The parameters savable (PS) bit is only used with the MODE SENSE command.
This bit is reserved with the MODE SELECT command. A PS bit of one indicates
that the target is capable of saving the page in a non-volatile vendor-
specific location.
The error recovery parameters for verify operations are as defined by the
read error recovery parameters (see 13.3.3.3).
13.4. Glossary for CD-ROM Devices
absolute F field. The sub-division of the S Field part of the absolute
physical address from the beginning of the media. One physical sector.
Written on CD-ROM media in binary coded decimal notation. The value is from
00bcd to 74bcd. (See MSF Address, Frame.)
absolute M field. The most significant part of the absolute physical address
from the beginning of the media. Written on CD-ROM media in binary coded
decimal notation. The value is from 00bcd to 74bcd. (See MSF Address.)
absolute S field. The intermediate significant part of the absolute physical
address from the beginning of the media. Written on CD-ROM media in binary
coded decimal notation. The value is from 00bcd to 59bcd. (See MSF Address.)
bcd. Binary Coded Decimal is the number system used on the physical CD-ROM
and CD-DA media. Numbers that use this notation have the 'bcd' suffix
attached. A byte has two four-bit values each of which can have a value from 0
to 9. The maximum value is 99bcd (99 decimal). Hence the maximum number of
tracks is 99bcd.
Example: 00 01 02 03 ... 08 09 10 11 ... 19 20 21 ... 98 99.
block. The term block refers to the data in one logical block - the number of
bytes defined by the logical block length in the mode block descriptor.
blocks per sector. The number of logical blocks read from each CD-ROM
physical sector. The value depends on the logical block Length as defined in
the mode block descriptor. The value for blocks per sector is:
1 if the logical block Length is 2048,
2 if the logical block Length is 1024,
4 if the logical block Length is 512, and
8 if the logical block Length is 256 bytes.
(Assuming a density code of 1 - 2048 bytes of data per sector.)
CD-DA. Compact Disc - Digital Audio. The standardized media for recording
digital audio information. The 'Red Book' defines CD-DA media.
CD-ROM. Compact Disc - Read Only Memory. CD-ROM is a standardized medium for
recording digitized audio and digital data. CD-ROM is used to describe media
with digital data rather than discs which encode audio only. The 'Yellow
Book' defines CD-ROM media.
CD-ROM control field. A four bit field in the Q sub-channel data indicating
the type of information encoded on the current track. Indicates audio versus
data and the type of audio encoding, etc. The control field is also found in
the Table of Contents entries. See Table 13-22.
CD-ROM data mode. A byte in the header of CD-ROM data sectors. This
indicates if data is present and if layered error correction information is
present. See Table 13-16.
CIRC. Cross Interleaved Reed-Solomon Code. The error detection and
correction technique used within small frames of audio or data. The CIRC
bytes are present in all CD-ROM Data Modes. The error correction procedure
which uses the CIRC bytes is referred to as the CIRC based algorithm. In most
CD-ROM drives, this function is implemented in hardware.
frame. A physical sector on CD-ROM media. Also the F field unit of a MSF CD-
ROM address. The term frame is also used in the CD-ROM model to describe the
amount of data received between synchronization patterns. 98 of these frames
make a sector. This sort of frame is referred to as 'small frames' where the
meaning is not clear from context.
hold track state. When a CD-ROM device enters the hold track state the
optical pick-up is maintained at an approximately constant position on the
media. This allows a paused operation to be resumed without latency due to
seeking. Rotational latency may be incurred, however.
index. Index Number. An index is a subdivision of a CD-ROM track. A track
can have from 1 to 99 index numbers. Index numbers within a track are
sequential starting with 1.
lead-in area. The area on a CD-ROM disc prior to track one. The main channel
in the lead-in area contains audio or data null information. This area is
coded as track zero but is not addressable via the SCSI command set. The Q
sub-channel in this area is coded with the table of contents information.
lead-out area. The area on a CD-ROM disc beyond the last information track.
The main channel in the lead-out area contains audio or data null information.
This area is coded as track AAbcd but is not addressable via the SCSI command
set. The READ CD-ROM CAPACITY data is the first logical block address of this
area minus one.
L-EC. Layered Error Correction. The error correction technique used with CD-
ROM Data Mode one sectors. In such sectors, 276 bytes of the auxiliary data
field contain L-EC bytes. The algorithm which uses these bytes to perform
error correction is often implemented in the drive firmware.
MSF Address. M Field / S Field / F Field. The physical address written on
CD-ROM discs. Expressed as a sector count relative to either the beginning of
the medium (absolute) or to the beginning of the current track (relative). As
defined by the CD-DA and CD-ROM standards, each F field unit is one physical
sector; each S field unit is 75 F field units; each M field unit is 60 S field
units. Valid contents of F fields are binary values from 0 through 74. Valid
contents of S fields are binary values from 0 through 59. Valid contents of M
fields are binary values from 0 through 74.
output port. A means for connecting the audio signal being played to
equipment outside the CD-ROM device.
pause area. A transition area at the beginning or end of an audio track
encoded with audio silence. This transition area is required where the audio
track immediately precedes a data track.
post-gap area. A transition area at the end of a data track encoded with null
information. This transition area is required where the data track
immediately precedes an audio track.
pre-gap area. A transition area at the beginning of a data track encoded with
null information. This transition area is required where the data track
immediately follows an audio track.
Red Book. Compact disc digital audio (CD-DA) media standard. Defines the
media formats and facilities to support the recording of digitized audio
information.
relative F field. The sub-division of the S field part of the relative
physical address from the beginning of the current track. One physical
sector. Written on CD-ROM medium in binary coded decimal notation. The value
is from 00bcd to 74bcd. (See MSF Address, Frame.)
relative M field. The most significant part of the relative physical address
from the beginning of the current track. Written on CD-ROM media in binary
coded decimal notation. The value is from 00bcd to 74bcd. (See MSF Address.)
relative S field. The intermediate significant part of the relative physical
address from the beginning of the current track. Written on CD-ROM medium in
binary coded decimal notation. The value is from 00bcd to 59bcd. (See MSF
Address.)
sector. Refers to the data contained during one frame time. (On CD-DA medium
with two channels of audio this is 1/75th of a second). In the CD-ROM
standard document the term block is used for this unit. There may be more
than one logical block per sector. Similarly, a single logical block may map
to multiple sectors.
sub-channel. CD-ROM and CD-DA media have a main channel and a sub-channel.
The sub-channel area has eight parts called P, Q, R, S, T, U, V, and W. The
Q-sub-channel contains information useful to the controller and drive, such as
the control field and MSF addresses. The data rate of each sub-channel (P, Q,
etc.) is 1/192nd of that of the main channel.
TOC. The table of contents has information on the type of disc and the
starting address of the tracks. This information is encoded in the Q sub-
channel.
track. Track Number. A track is a sub-division of the CD-ROM media. A disc
has from one to ninety-nine tracks. The data within a track is always of the
same type. A track can contain be either CD-ROM or CD-Audio. A disc can
start at any track number.
track relative logical address. An offset from the beginning of the recorded
information on a track expressed in units of the logical block length. The
value is used to address logical blocks relative to the beginning of a track
using the relative MSF address encoded in the CD-ROM Q sub-channel.
transition area. Sectors at the beginning or end of tracks coded with null
information. Where required by the media standards, these areas have minimum
lengths of 1 or 2 seconds. The maximum lengths are not specified. Transition
areas at the beginning of a track are encoded with Index zero. Addresses
within transition areas may not be read.
Yellow Book. A standard (IEC 108) which defines CD-ROM media. The Yellow Book
defines the media formats and facilities that support the recording of digital
data on Compact Disc media.