Sony SDX-800V/R User Manual

Page of 206
LOG SENSE 
6.Command Specification
SONY AIT-3Ex drive SDX-800V series Ver.1.1 
 
6-15 
Table 6-10: Log Page Format 
 Bit 
Byte 
7 6 5 4 3 2 1 0 
Reserved Page 
Code 
Reserve 
(MSB)  
 
Page Length (n-3) 
(LSB) 
 
Log Parameters (s) 
4  
x+3 
The First Log Parameter 
(Length x) 
 
n-y 
The Last Log Parameter 
(Length y) 
Page code: Identifies which page of data is being transferred. If the Page Code field value is reserved or not 
implemented by the target, the target shall terminate the command with a CHECK CONDITION status. The sense 
key shall be set to ILLEGAL REQUEST, and the additional sense code shall be set to INVALID FIELD IN 
PARAMETER LIST. 
Page Length: The Page Length field indicates the total number of bytes that follow this byte.  The value returned for 
this field depends on the value you specified for the Page Code and the Parameter Pointer in the CDB. This value is 
independent of what you specified for the Allocation Length. A Page Length value that results in the truncation of any 
parameter shall cause the target to terminate the command with CHECK CONDITION status. The sense key shall 
be set to ILLEGAL REQUEST and the additional sense code shall be set to INVALID FIELD IN PARAMETER LIST.  
6.6.2.  The Log Parameter Descriptor 
Most log pages contain one or more special data structures called log parameters. These may be data counters 
which record the occurrence of certain events, or they may be more complex structures which describe activities or 
other events which occur within the device. Each parameter structure begins with a 4-byte parameter header 
followed by one or more bytes of parameter structure data. The 4-byte header is shown below: 
Table 6-11: Log Parameter 
Bit 
Byte 
7 6 5 4 3 2 1 0 
(MSB) Parameter 
Code 
 
  
(LSB) 
DU 
DS (1) 
TSD 
ETC (0)
TMC (00) 
LBIN 
LP 
Parameter Length (n-3) 
 Parameter 
Value  
 
 
 
Parameter Code: Identifies which parameter of data is being transferred. If the parameter code value is reserved or 
not implemented by the target, then the target shall terminate the command with CHECK CONDITION status. The 
sense key shall be set to ILLEGAL  REQUEST and the additional sense code shall be set to INVALID FIELD IN 
PARAMETER LIST. 
The DU, DS, TSD, ET, TMC, and LP fields are collectively referred to as the control byte. 
DU: The DU bit (Disable Update) is not defined for threshold values (indicated by the PC field of the LOG SENSE 
command descriptor block). The target shall ignore the value of any DU bits in a LOG SELECT command. 
DS: The DS (Disable Save) bit informs the initiator that savable parameters are disabled (i.e. not supported), and 
should always be 1. If it is 0 the  command will terminate with CHECK CONDITION status with sense key set to 
ILLEGAL REQUEST and additional sense code of ILLEGAL FIELD IN PARAMETER LIST.