Length Fields; Data-Phase Command Contents - Maxtor ATLAS 10K III Product Manual

SCSI Description
Many of the SCSI commands cause data to be transferred between the initiator and
the drive. The content and characteristics of this data are command-dependent. Table
5-8 lists the information transmitted for all of the commands.
The "Length in CDB" column of Table 5-8 identifies the Command Descriptor
Block field used by the drive to determine how much command-related data are to
be transferred. The units (bytes or logical blocks) for the different Length fields are
implied by the Length Field Name as shown in Table 5-7:
Allocation Length
Parameter List Length
Transfer Length
Byte Transfer Length
The DATA OUT column in Table 5-8 lists the information passed to the drive by the
initiator as part of the command. The DATA IN column lists the information sent to
the initiator by the drive.
Numbers in parentheses after an item indicate the item's length in bytes. In some cases,
additional length information is communicated during the DATA phase. For example,
a FORMAT UNIT Defect List Header contains a Defect List Length field that
contains the total length of the Defect Descriptors that follow the Defect List Header.
Table 5-8 does not include these cases.
CHANGE
DEFINITION
FORMAT UNIT
INQUIRY
Parameter List
LOG SELECT
LOG SENSE
Parameter List
MODE SELECT
MODE SENSE
PERSIST. RES. IN
PERSIST. RES.
OUT
READ (6) (10)
5-10 Maxtor Atlas 10K III
T a b l e 5 - 7 Length Fields
Bytes of data the drive is allowed to send to the initiator
Bytes of data the initiator has available for the drive
Logical data sectors the initiator wants transferred or verified
Bytes of data the initiator wants transferred
T a b l e 5 - 8 DATA-Phase Command Contents
0
Defect List Header
0 Initialization Pattern (6-8)
Defect Descriptors
Allocation
(must be 0)
Allocation
Mode Parameter Header
(4 Block Descriptor (8
Page(s))
Allocation
Transfer
--
Standard Inquiry or a Vital Prod-
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uct Data page
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Block Descriptor (8)
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--
Log Page
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Data