Travelstar 4K120 Hard Disk Drive Specification
88
11.14 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 maximum.
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 or hard 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 is dispersed.
11.14.1 Auto Reassign Function
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.
Nonrecovered 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.
Nonrecovered read errors
When a read operation fails after a 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 verifications 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 fails once and then is 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
predefined conditions.
Summary of Contents for HTS421210H9AT00
Page 2: ......
Page 20: ...Travelstar 4K120 Hard Disk Drive Specification 6 ...
Page 21: ...Travelstar 4K120 Hard Disk Drive Specification 7 Part 1 Functional specification ...
Page 22: ...Travelstar 4K120 Hard Disk Drive Specification 8 ...
Page 24: ...Travelstar 4K120 Hard Disk Drive Specification 10 ...
Page 38: ...Travelstar 4K120 Hard Disk Drive Specification 24 ...
Page 71: ...Travelstar 4K120 Hard Disk Drive Specification 57 Part 2 Interface specification ...
Page 72: ...Travelstar 4K120 Hard Disk Drive Specification 58 ...
Page 74: ...Travelstar 4K120 Hard Disk Drive Specification 60 ...
Page 76: ...Travelstar 4K120 Hard Disk Drive Specification 62 ...
Page 104: ...Travelstar 4K120 Hard Disk Drive Specification 90 ...
Page 110: ...Travelstar 4K120 Hard Disk Drive Specification 96 ...
Page 200: ...Travelstar 4K120 Hard Disk Drive Specification 186 Table 131 Selective self test log ...
Page 212: ...Travelstar 4K120 Hard Disk Drive Specification 198 ...
Page 224: ...Travelstar 4K120 Hard Disk Drive Specification 210 ...
Page 232: ...Travelstar 4K120 Hard Disk Drive Specification 218 ...
Page 238: ......