Reassign Function; 48-Bit Address Feature Set - Hitachi 7K320 - Travelstar Mobile Hard Drive Specifications

the data into its buffer. The device assumes responsibility to write the data subsequently onto the
disk.
 While writing data after completed acknowledgment of a write command, soft reset or COMRESET
does not affect its operation. But power off terminates writing operation immediately and unwritten data
are to be lost.
 Flush cache, Soft reset, Standby, Standby Immediate and Sleep are executed after the completion of
writing to disk media on enabling write cache function. So the host system can confirm the completion
of write cache operation by issuing flush cache command, Soft reset, Standby command, Standby
Immediate command or Sleep command, and then, by confirming its completion.
12.13

Reassign Function

The reassign Function is used with read commands and write commands. The sectors of data for
reassignment are prepared as the spare data sector. The one entry can register 256 consecutive
sectors maximally.
This reassignment information is registered internally, and the information is available right after
completing the reassign function. Also the information is used on the next power on reset.
If the number of the spare sector reaches 0 sector, the reassign function will be disabled
automatically.
The spare tracks for reassignment are located at regular intervals from Cylinder 0. As a result of
reassignment, the physical location of logically sequenced sectors will be dispersed.
Auto Reassign Function
12.13.1
The sectors that show some errors may be reallocated automatically when specific conditions are met.
The spare tracks for reallocation are located at regular intervals from Cylinder 0. The conditions for
auto-reallocation are described below.
Non recovered write errors
When a write operation can not be completed after the Error Recovery Procedure(ERP) is fully
carried out, the sector(s) 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 sectors, the write cache function will be disabled
automatically.
Non recovered 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 the 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 then recovered at the specific ERP step, this sector of
data is reallocated automatically. A media verification sequence may be run prior to the relocation
according to the pre-defined conditions.
12.14

48-bit Address Feature Set

The 48-bit Address feature set allows devices with capacities up to 281,474,976,710,655 sectors. This
allows device capacity up to 144,115,188,075,855,360 bytes. In addition, the number of sectors that
may be transferred by a single command are increased by increasing the allowable sector count to 16
bits.
Commands unique to the 48-bit Address feature set are:
Page 66 of 176
7K320 SATA OEM Specification