Browse Prior Art Database

Power Save Operation

IP.com Disclosure Number: IPCOM000104730D
Original Publication Date: 1993-May-01
Included in the Prior Art Database: 2005-Mar-19
Document File: 2 page(s) / 51K

Publishing Venue

IBM

Related People

Asano, H: AUTHOR

Abstract

This article describes the one method to save Hard Disk Drive (HDD) power. Current HDD has power mode, operation(such as read, write, seek, etc.), idle, standby (VCM off), sleep (Spindle motor off, VCM off), shutdown (VCM off, Spindle motor off, No host interface active), etc.

This text was extracted from an ASCII text file.
This is the abbreviated version, containing approximately 82% of the total text.

Power Save Operation

      This article describes the one method to save Hard Disk Drive
(HDD) power.  Current HDD has power mode, operation(such as read,
write, seek, etc.), idle, standby (VCM off), sleep (Spindle motor
off, VCM off), shutdown (VCM off, Spindle motor off, No host
interface active), etc.

      When the command is issued from the host to the HDD in sleep or
standby mode, HDD with this method has the decision circuit whether
the command can be processed without changing the power mode using
the data in the sector buffer.

      If the command from the host is seek operation with the HDD in
standby or sleep mode, seek completion will be returned to the host
without actual seek operation but just changing the current
Head/cyl/sector pointer.  In read operation, HDD will first check the
data stored in the sector buffer or not.  If the target sector is
found, data from the sector buffer to the host will be performed
without changing the power mode.

      In write operation, there are two approaches depending on the
user application.  1) the sector buffer is configured with the
volatile memory : check the target sector resides in the sector
buffer.  If the transferred data is exactly same as the stored data,
no actual write operation will happen and return the completion
status to the host.  Only the data being different, actual write
operation will be performed.  2) the sector buffer is configured with
the non-volatile memory or write dat...