A method to execute SAT (Surface Analysis Test) within a fixed time
Publication Date: 2005-Aug-31
The IP.com Prior Art Database
A method to reduce manufacturing test time of hard disk drive is disclosed. A function implemented to realize 'Read Continuous' is used for the method.
A method to execute SAT (Surface Analysis Test ) within a fixed time
When a hard disk drive is produced, all defective sectors must be found in the manufacturing process. The process to find defective sectors is called SAT (Surface Analysis Test). To find defective sectors, all sectors are read many times. When a read operation stops by a read error, the error location is registered, and the read operation is resumed from the next sector. It takes one extra revolution time of the media always when a read error occurs.
Since a defective sector causes ECC uncorrectable read error almost always when it is read, the time period to find all defective sectors can be determined by the number of defective sectors. If there are many defective sectors in a hard disk drive, the manufacturing test time of the drive can be much longer than that of a drive with fewer defective sectors.
A function to ignore ECC related errors are implemented to support 'Read Continuous'. When the function is enabled, all ECC related errors are ignored. By adding a function to leave ignored error information, a read operation completes always without being stopped by read errors, and all error information can be obtained after the completion. By using the function the manufacturing test time can be reduced and the variance of the test time can be reduced, too.
Disclosed by Hitachi Corporation