Browse Prior Art Database

Seek Ahead operation

IP.com Disclosure Number: IPCOM000013082D
Original Publication Date: 2000-Feb-01
Included in the Prior Art Database: 2003-Jun-12
Document File: 2 page(s) / 27K

Publishing Venue

IBM

Abstract

Disclosed is a method of starting a seek operation for a command which is queued before a completion of current operation under queued random operation. This method reduce a command overhead to start seek and improve a command handling performance.

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Seek Ahead operation

Disclosed is a method of starting a seek operation for a command which is queued before a
completion of current operation under queued random operation. This method reduce a command
overhead to start seek and improve a command handling performance.

A distinctive feature of this method is to start seek operation before a completion of current
disk read/write operation. To achieve this, a Hard Disk Controller(HDC) includes a function to
detect a servo sector which is set by software prior to start operation and a function to inform
the event (Following Complete: FCOMP) to software.

  The following procedure describes a current method of starting seek operation for a command
which is queued.

1. Wait Drive Complete(DCOMP) event to detect a completion of disk
read/write.

2. Invoke a seek request operation for a queued command.

3. Servo pick up a seek request and start seek operation.

This means that there is at lest one servo sector delay to start
seek operation.

  The following procedure describes a disclosed method of starting seek operation for a command
which is queued.

1. Set Servo ID prior to start disk read/write operation to HDC.

2. Wait Following complete(FCOMP) event to detect a completion of
following operation required to perform disk read/write operation.

3. Invoke a seek request operation for a queued command.

4. Servo pick up a seek request and start seek operation.

This means that there is no delay to start seek operation after DCOMP.

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