Browse Prior Art Database

Dual Settle Timeout Criteria for Driect Access Storage Devices

IP.com Disclosure Number: IPCOM000110804D
Original Publication Date: 1994-Jan-01
Included in the Prior Art Database: 2005-Mar-26
Document File: 2 page(s) / 52K

Publishing Venue

IBM

Related People

Mataitis, EE: AUTHOR [+4]

Abstract

Disclosed is a dual position window for disk drive settle complete algorithm. The position error tolerance is increased after a period of time to allow detection of settle completion in the presence of significant position error.

This text was extracted from an ASCII text file.
This is the abbreviated version, containing approximately 65% of the total text.

Dual Settle Timeout Criteria for Driect Access Storage Devices

      Disclosed is a dual position window for disk drive settle
complete algorithm.  The position error tolerance is increased after
a period of time to allow detection of settle completion in the
presence of significant position error.

      The disk drive utilizes a settle completion criteria to
determine when an access to a desired track has completed, and the
data heads are maintaining a safe-to-write position.  Following
arrival at the desired location, the settle is considered to be
complete when the position error has remained within the settle
window, defined as an acceptable position error for a selected number
of consecutive sample times.  The position tolerance and number of
consecutive samples are selected to assure nominal written track
position accuracy, yet achieve settle completion within a fraction of
one revolution time.

      In cases where significant position error exists, such as
during operational vibration, the settle completion criteria may not
be met within a reasonable period of time using the "nominal"
position error tolerance.

      During the first period allowed for settle completion, the
"nominal" position tolerance is used.  After this time the position
tolerance is increased and the criteria is checked for an additional
period of time, thereby allowing for detection of settle completion
under conditions of sustained extreme position error.

      An ex...