Hitachi Ultrastar 15K450 (FC-AL) Hard Disk Drive Specification
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19.27 RECEIVE DIAGNOSTICS RESULTS (1C)Table 202:RECEIVE DIAGNOSTIC RESULTS (1C)
The RECEIVE DIAGNOSTIC RESULTS command requests that analysis data requested by a SEND DIAGNOSTIC com-
mand be sent to the Initiator.
•PCV (Page Code Valid) bit of zero indicates that the most recent SEND DIAGNOSTIC command shall define the
data returned by this command. PCV bit of one indicates that the contents of the Page Code field shall define the data
returned by this command.
•Allocation Length specifies the amount of data to be returned to the Initiator. This value may be zero and this is not
considered an error. The Target terminates the Data In phase when all available data has been transferred or when the
number of bytes transferred equals the Parameter List Length.
This command may also be used to retrieve a Diagnostic Page from an enclosure.
When requested to communicate with the enclosure via the Send and RECEIVE DIAGNOSTIC commands, the Target goes
through a 'discovery phase' with the enclosure as defined in the SFF-8067 standard. The results of this 'discovery phase', deter-
mine whether the enclosure: 1) does not support Enclosure Services, 2) supports only the 'short' Enclosure Service mode as
defined by SFF-8045, or 3) supports the 'long' Enclosure Service mode as defined by SFF-8067. After the 'discovery phase' the
drive behaves in accordance with the Enclosure Service mode capabilities of the enclosure. The drive does not attempt to
remember the Enclosure Service capabilities of the enclosure, but rather, in accordance with the SFF-8067 standard, re-per-
forms the 'discovery phase' for each Send and RECEIVE DIAGNOSTIC command received.
If the Target determines that the enclosure does not support Enclosure Services, any attempts to access the Diagnostic Pages in
the enclosure will result in CHECK CONDITION status and sense data is built with the Sense Key and Additional Sense Code
indicating ENCLOSURE SERVICES UNAVAILABLE. In this case, only the Diagnostic Pages supported by the Target may
be requested.
If the Target determines that the enclosure supports the 'short' form of Enclosure Services, Diagnostic Page 08h is returned in
response to a request for any valid Diagnostic Page (i.e. 01h-0Fh).
If the Target determines that the enclosure supports the 'long' form of Enclosure Services, a request for the page is passed on to
the enclosure. Any diagnostic information returned to the Target is transferred to the Initiator. If the request for enclosure
transfer fails, the command is terminated with CHECK CONDITION status and sense data is built with the Sense Key and
Additional Sense Code indicating ENCLOSURE SERVICES UNAVAILABLE.
Byte Bit
76543210
0 Command Code = 1Ch
1 Reserved = 0 Reserved = 0 PCV
2 Page Code
3
4
(MSB) Allocation Length
(LSB)
5 VU = 0 Reserved = 0 FLAG LINK