User Manual

SCSI Commands Reference Manual, Rev. J 307
www.seagate.com Parameters for direct access devices
5.2.2.2.2.2 Parameter control byte values for bounded data counter parameters
The device server shall return LOG SENSE parameter control byte values and process LOG SELECT parameter control byte values as shown in table
269 for any log parameter that is defined to be a bounded data counter log parameter.
If a LOG SELECT command contains a bounded data counter log parameter in which the parameter control byte values differ
from those shown in table 269, then the command shall be terminated with CHECK CONDITION status, with the sense key set to
ILLEGAL REQUEST, and the additional sense code set to INVALID FIELD IN PARAMETER LIST.
Each bounded data counter log parameter contains one saturating counter that is:
a) associated with one or more events; and
b) incremented whenever one of these events occurs.
If the counter in a bounded data counter log parameter has associated with it a vendor specific maximum value, then upon
reaching this maximum value, the data counter shall not be incremented (i.e., its value does not wrap).
If the counter in a bounded data counter log parameter reaches its maximum value (i.e., saturates), the device server shall:
a) set the DU bit to one;
b) handle other bounded data counter log parameters in the log page based on the contents of the FORMAT AND LINKING field in each
other log parameter as follows:
A. if the FORMAT AND LINKING field is set to 00b, then that other log parameter shall stop incrementing until reinitialized
by a LOG SELECT command; or
B). if the FORMAT AND LINKING field is set to 10b, then that other log parameter shall not stop incrementing, but may be
reinitialized by a LOG SELECT command.
and
c) not alter the handling of other log parameters in the log page that are:
A. unbounded data counter log parameters (see 5.2.2.2.2.3);
B). ASCII format list log parameters (see 5.2.2.2.2.4); and
C). binary format list log parameters (see 5.2.2.2.2.5).
The processing of a command shall not be altered because the counter in a bounded data counter log parameter reaches its
maximum value (i.e., saturates). If the RLEC bit is set to one in the Control mode page (see 5.3.12) and the processing of a
command encounters no exception conditions other than the counter in a bounded data counter log parameter reaching its
maximum value, then the command shall be terminated with CHECK CONDITION status, with the sense key set to RECOVERED
ERROR, and the additional sense code set to LOG COUNTER AT MAXIMUM.
Table 269 Parameter control byte values for bounded data counter parameters
Field or bit
Value for
LOG SENSE
Value for
LOG SELECT
Description
DU 0 or 1 0 or 1
When the DU bit is set to zero, the device server shall update the log parameter value to
reflect all events that should be noted by that parameter. When the DU bit is set to one, the
device server shall not update the log parameter value except in response to a LOG SELECT
command that specifies a new value for the parameter.
TSD 0 or 1 0 or 1
When the TSD bit is set to zero, the device server shall save the log parameter to its
medium at vendor specific intervals. When the TSD bit is set to one, implicit saving of the
log parameter is disabled by an application client.
FORMAT
AND
LINKING
00b or 10b 00b or 10b
The log parameter is a data counter (see table 268) and the handling of a parameter that
reaches its maximum value is described in this subclause.