Hitachi HUS154530VLF400 Manual De Usuario

                                    

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

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The Read-Write recovery parameters that will be used during any command that performs a read or write operation to the 
medium are as follows:

• AWRE  Automatic Write Reallocation Enabled bit, set to zero indicates that the drive shall not perform automatic reallo-

cation of defective data blocks during write operations. An AWRE bit set to one indicates that the drive shall perform 
automatic reallocation of defective data blocks during write operations.

• ARRE  Automatic Read Reallocation Enabled bit, set to zero indicates that the drive shall not perform automatic reallo-

cation of defective data blocks during read operations. ARRE bit set to one indicates that the drive shall perform 
automatic reallocation of defective data blocks during read operations.

• TB  Transfer Block bit, set to one indicates that a data block that is not recovered within the recovery limits specified 

shall be transferred to the Initiator before Check Condition status is returned. A TB bit set to zero indicates that such 
a data block shall not be transferred to the Initiator. Data blocks that can be recovered within the recovery limits are 
always transferred regardless of the value of the bit.

• RC  Read Continuous bit, set to one requests the Target to transfer the entire requested length of data without adding 

delays that would increase or ensure data integrity. This implies that the Target may send erroneous data. This bit has 
priority over all other error control bits (PER, DTE, DCR, TB). RC set to zero indicates normal interpretation of 
PER, DTE, DCR, and TB values. The RC bit setting is used by the Target when reporting errors associated with the 
transfer of the Initiator's data for the Read commands interpretation of PER, DTE, DCR, and TB values.  The RC bit 
applies only to READ commands.

Note: The Target implementation of the RC option is to disable error detection of the data fields but continue normal 
error detection and recovery for errors occurring in the servo field. If a servo field failure occurs, normal DRP could 
result in considerable recovery action, including proceeding through all levels of DRP.

• EER an Enable Early Recovery bit, must be set to zero, indicating that the drive shall use an error recovery procedure 

that minimizes the risk of misdetection or miscorrection during the data transfer. Data shall not be fabricated.