Browse Prior Art Database

Quick Standby and Resume

IP.com Disclosure Number: IPCOM000118871D
Original Publication Date: 1997-Aug-01
Included in the Prior Art Database: 2005-Apr-01
Document File: 2 page(s) / 47K

Publishing Venue

IBM

Related People

Kakihara, T: AUTHOR [+4]

Abstract

Disclosed is a new method for an Integrated Drive Electronics (IDE) Hard Disk Drive (HDD) to reduce its transition time from a standby state to an operational or an idle state. To shorten the transition time, the spindle motor of the HDD in the standby state of this method keeps rotating at the lowest speed (standby level) that maintains enough fly height of magnetic heads flying over the disks. Its power consumption in the standby state becomes lower by the slower rotational speed than that in the operational or idle state.

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Quick Standby and Resume

      Disclosed is a new method for an Integrated Drive Electronics
(IDE) Hard Disk Drive (HDD) to reduce its transition time from a
standby state to an operational or an idle state.  To shorten the
transition time, the spindle motor of the HDD in the standby state of
this method  keeps rotating at the lowest speed (standby level) that
maintains enough fly height of magnetic heads flying over the disks.
Its power consumption in the standby state becomes lower by the
slower rotational  speed than that in the operational or idle state.

      The Figure shows the flowchart of this quick standby and resume
method.  When an HDD receives Standby Immediate Command from a system
or when its standby timer whose value the system sets with Standby
Command expires during the operational or idle state (1), the heads
seek to a certain standby position where their fly height can be
maintained high enough during the standby state which sets slower
rotational speed  (2).  After the heads-seeking, the HDD answers the
command completion in  case of Standby Immediate Command (3) and
starts to slow the spindle rotational speed down to the standby
level.  Then, it enters the standby  state after reaching the standby
level speed successfully (4).

      During the standby state, an HDD seeks the standby position
with some interval (5) to keep the fly height high enough.

      A reset or a command which needs disk access from the system
triggers...