Page Control Field - Quantum LTO 2 User Manual

Page Control Field

LTO-2 SCSI Interface Guide
Field Bytes
Parameter 5-6
Pointer
Allocation 7-8
Length
Reserved
Control
The Page Control (PC) field specifies the type of counters that the initiator
2
is requesting. The value 01b is the most common page control setting.
This requests the accumulated counts for the page to be returned. These
counts reflect the current count of events since the last power-on cycle,
SCSI bus Reset, Bus Device Reset, Target or Logical Unit Reset, Reset LIP,
cartridge loading, or the last
parameter values.
Accumulated values are incremented by the drive as an event occurs. For
pages 02h, 03h, and 32h, these values can be cleared with all the above
methods. For page 0Ch these values can be cleared with all the above
methods except with
accumulated values in volatile memory, the values may be lost if a power
cycle occurs.
The PC field is ignored for pages 00h, 0Ch, 14h, 16h, 2Eh, 30h, 31h, and
33h, 3Ah, and 3Ch and the accumulated values are always returned
except page 00h, which has no accumulated values.
Bits Description
7-0 Specifies the beginning parameter code
to be returned to the initiator. All
remaining parameter codes are returned
in ascending order.
This field is ignored for page code 00h.
7-0 The Allocation Length field specifies the
maximum amount of memory space (in
bytes), which the initiator has reserved
for
LOG SENSE
The drive returns the number of bytes
contained in the requested page, or the
requested Allocation Length, whichever
is less. If the Allocation Length is less
than the actual page length, the transfer
is truncated.
All reserved bits must be 0.
9 See Control Byte Format on page
LOG SELECT
. Because the drive maintains the
LOG SELECT
Chapter 2 SCSI Commands
LOG SENSE Command
data.
command that cleared the
29.
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