Hitachi HUS154530VLF400 用户手册

                                    

Hitachi Ultrastar 15K450 (FC-AL) Hard Disk Drive Specification

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Fields marked in the table as 'Ignored' are not used or checked by the drive. They will be initialized to zero but can be set as 
desired for compatibility with older drives.

• MRG (Merge Glist into Plist) bit is set to 1 for merging the Glist entries into the Plist during FORMAT UNIT command.

• VGMDE (Veggie Mode) bit set to 1 will cause the drive to execute random self-seeks.  To enable this mode, the initiator 

must perform the mode select to set the bit while the drive is spinning, then Stop Unit, then Start Unit.  VGMDE set 
to 0 disables the self-seeks (normal operation).

• RRNDE (Report Recovered Non Data Errors) bit controls the reporting of recovered Non Data Errors when the PER bit 

is set. If RRNDE is set, recovered Non Data Errors are reported. If the RRNDE bit is not set, then recovered Non 
Data Errors are not reported.

• FDD  (Format Degraded Disable) controls the reporting of Format Degraded sense data for Test Unit Ready commands 

when the drive is in a format degraded state.  When the FDD bit is one, Format Degraded sense data will not be 
reported for a Test Unit Ready command.  When the FDD bit is zero, Format Degraded sense data will be reported 
for Test Unit Ready commands  when the drive is in a format degraded state.  This bit does not affect the reporting of 
Format Degraded conditions for any media access commands.

• CAEN (Command Aging Enable) When set this bit causes the Command Age Limit timer to be used to avoid commands 

waiting in the command queue for an indefinite period. When commands have been in the queue for a period of time 
greater than the timer limit they will be reordered to be executed on a first come first served basis. When this bit is 
reset, commands are always executed based on the queue reordering rules.