Fujitsu MAT3300FC 用户手册

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5.1   Sense Data 
C141-C008 
5-3 
5.1.2  Sense data basic information 
Bytes 0 to 17 of the sense data are basic information which show the contents of 
the error that has occurred.  The INIT can know the contents of the error and the 
key information that is necessary for recovery processing by analyzing this basic 
information.  Each field and the meanings of bits in the sense data basic 
information are explained below. 
(1) Valid 
When this bit is “1,” it indicates that the values shown in the information field 
(bytes 3 to 6) are valid.  On the other hand, when this bit is “0”, it indicates that 
the information field does not contain valid information. 
(2) Error code 
This field shows the format and type of sense data.  The IDD always displays X 
‘70’ (current error) or X ‘71’ (deferred error), which has the meaning “expanded 
sense data format” in this field. 
(3)  ILI (incorrect length indicator)  
When this bit is “1,” it indicates that the transfer byte length requested in the 
command did not coincide with the data block length on the disk media. In the 
IDD, the only commands that it reports “1” in this bit for are the READ LONG 
command and the WRITE LONG command.  For details, refer to the descriptions 
of these commands (Sections 4.4.5 and 4.4.6). 
(4) Sense key 
This field shows the cause of the sense data being generated.  More details 
reasons are indicated in the sense code field (Byte 12) and the sub-sense code 
field (Byte 13).  Table 5.3 shows a list of the meanings of sense keys. 
(5) Information 
This field shows information related to the error that has been detected and is 
valid only when the Valid bit is “1.”  Depending on the command where the error 
occurred, additional information other than the information in this field may be 
indicated in the command inherent information field.  The information shown in 
this field has the following meanings depending on the value of the “ILI” bit. 
a)  When the “ILI” bit is “0,” the logical block address of the data block where 
the error occurred is indicated. 
b)  When the “ILI” bit is “1,” the difference between the transfer byte length 
requested by the command and the actual data block length on the disk media 
is indicated.  If the difference is a minus value, (if the request transfer byte 
count is smaller), it is expressed as a complement of 2.  In the IDD, only the 
READ LONG command and the WRITE LONG command display this 
information.  For details, see the descriptions of these commands (Sections 
4.4.5 and 4.4.6).