Datasheet
12.11 Reassign Function
The Reassign Function is used with read and write commands. The sectors of data for reassignment are
prepared as the spare data sector. There are 448 spare sectors. One entry can register a maximum of
256 consecutive sectors.
This reassignment information is registered internally and the information is available upon completing
the reassign function. The information is also used on the next power on reset or hard reset.
If the number of the spare sectors reaches 0, the reassign function will be disabled automatically.
The spare sectors for reassignment are located in a reserved area. As a result of reassignment the
physical location of logically sequenced sectors is dispersed.
12.11.1 Auto Reassign Function
The sectors that show some errors may be reallocated automatically when specific conditions are met.
The spare sectors for reallocation are located in the reserved area. The conditions for auto-reallocation
are described below.
Nonrecovered write errors
When a write operation can not be completed after the Error Recovery Procedure (ERP) is fully carried
out the sectors are reallocated to the spare location. An error is reported to the host system only when
the write cache is disabled and the auto reallocation fails.
If the number of available spare sectors reaches 16 the write cache function is disabled automatically.
If the command is without retry and the write cache function is disabled the auto reassign function is not
invoked.
Nonrecovered read errors
When a read operation fails after defined ERP is fully carried out a hard error is reported to the host
system. This location is registered internally as a candidate for reallocation. When a registered location is
specified as a target of a write operation, a sequence of media verification is performed automatically.
When the result of this verification meets the criteria this sector is reallocated.
Recovered read errors
When a read operation for a sector failed once and then is recovered at the specific ERP step then this
sector of data is reallocated automatically. A media verification sequence may be run prior to the reloca-
tion according to the predefined conditions.
Hard disk drive specification for DSCM-11000/-10512/-10340
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