Log page format – HP Q153090901 User Manual
Page 58
Commands
58
Log page format
All log pages except Page 0 consist of a page code header followed by a number of parameters.
The page header has the following format:
The Page Code specifies which Log page is being returned. The Page Length indicates the number
of additional bytes in the parameters.
For the
Log Select
command only, the four bytes shown above are sent for each log page to be
cleared. The Page Length field should be set to zero.
For the
Log Sense
command one or more parameters is sent. See the actual page descriptions
above for more information. Note that all the parameters for a particular page must be sent. Each
parameter has the following format:
Parameter
Pointer
0
All parameters are returned.
n
Parameter data of a specified log page is returned in ascending order
beginning from this code. If this code is larger than the largest
parameter in the page, the drive will return
CHECK CONDITION
with
additional sense of 2400h (Invalid Field In CDB).
Allocation
Length
The Allocation Length field specifies the maximum number of bytes of data that should
be returned to the host. The drive will return the entire log or Allocation Length bytes,
whichever is the lesser.
7
6
5
4
3
2
1
0
0
Page Code
1
Reserved (0)
2
(MSB)
Page Length
3
(LSB)
7
6
5
4
3
2
1
0
0
(MSB)
Parameter Code
1
(LSB)
2
DU (0)
DS (1)
TSD (0)
ETC (0)
TMC(0)
Rsvd (0)
LP (0)
3
Parameter Length (n
−
3)
4
(MSB)
Parameter Bytes
n
(LSB)
Parameter Code
A two-byte value that uniquely identifies the parameter within the log.
DU, TSD, ETC, TMC
and LP
0 Must be zero. For a full description of these fields refer to the SCSI-2
standard.
DS
1 Must be 1, indicating that drive will maintain the saving of data itself. Note
that the host must set the SP bit to 1 in a LOG SELECT command, otherwise a
CHECK CONDITION will result.