Browse Prior Art Database

Automatic Power Down for Hard Disk Drive with Small Computer System Interface

IP.com Disclosure Number: IPCOM000111452D
Original Publication Date: 1994-Feb-01
Included in the Prior Art Database: 2005-Mar-26
Document File: 2 page(s) / 52K

Publishing Venue

IBM

Related People

Iwasa, H: AUTHOR [+3]

Abstract

Disclosed is a method to reduce the power dissipation and software complexity of a Hard Disk Drive (HDD) employing a Small Computer System Interface (SCSI). The proposed SCSI interface (I/F) block is automatically activated/deactivated without any intervention of the other blocks of HDD.

This text was extracted from an ASCII text file.
This is the abbreviated version, containing approximately 100% of the total text.

Automatic Power Down for Hard Disk Drive with Small Computer System
Interface

      Disclosed is a method to reduce the power dissipation and
software complexity of a Hard Disk Drive (HDD) employing a Small
Computer System Interface (SCSI).  The proposed SCSI interface (I/F)
block is automatically activated/deactivated without any intervention
of the other blocks of HDD.

      Fig. 1 shows a typical hardware configuration of HDD with SCSI
interface block (1).  For control block (2), data path block (3) and
servo block (4), the power supply can be controlled by HDD itself.
But in SCSI BUS RESET condition or SELECTION phase, the I/F block (1)
must be activated even if it is in the Sleep (=power down) state.  In
conventional HDD, when these conditions are detected, the I/F block
(1) activates the control block (2).  The block (2) performs the
required operation according to the condition, and it deactivates the
I/F block (1) after the completion of the operation.

      But in the SCSI SELECTION PHASE, if the HDD is not selected, no
operation is required.  So if the I/F block (1) can be deactivated by
itself, no other blocks have to be activated.  Then no power supply
and no software support for this condition are required.

Fig. 2 shows the state of the blocks during the RESET and SELECTION
phases.