Table of Contents
Advertisement
CDU-541 CD-ROM DRIVE SCSI INTERFACE MANUAL
5.2. 30. SEEK Co_and
==============================================================================
Bitl
Byte
I
7
6
5
4
3
2
1
o
==============================================================================
o
I
Operation Code (OBh)
:
-----1-----------------------------------------------------------------------1
1
:
Logical Unit Number
: (MSB)
1
-----1------------------------------
---I
2
:
Logical Block Address
I
-----1---
---I
3
I
(LSB) :
-----1-----------------------------------------------------------------------1
4
I
Reserved
.
I
-----1-----------------------------------------------------------------------:
5
I
Control Byte
:
==============================================================================
The SEEK command requests that the controller position the optical pick-up
at logical block address specified and enter the hold track state for the
duration of the inactivity time.
A seek operation may be requested to any logical block address that is less
than or equal to that reported by a READ CAPACITY command.
If the logical
block address is within a data track then the address will be verified against
the header address.
If the logical block address is within an audio track it
is first converted into a Q
sub-ch~-~el
gddress
~~d
the seek is performed to
that address.
The
Q
sub-channel address has a tolerance of
~
75 blocks.
If the disconnect privilege is granted the controller will disconnect before
performing the seek operation.
If the ready condition does not exist a CHECK CONDITION status will be
returned and the appropriate additional sense code set.
If the logical block address requested exceeds that reported by the READ
CAPACITY data a CHECK CONDITION status will be returned.
The sense key is set
to ILLEGAL REQUEST and the additional sense code is set to LOGICAL BLOCK
ADDRESS NOT VALID.
If the drive is unable to complete the seek operation a CHECK CONDITION
status will be returned.
The sense key is set to MEDIUM ERROR and the
additional sense code is set to ERROR OCCURRED DURING SEEK OPERATION.
5-56
Advertisement
Table of Contents
