Browse Prior Art Database

Enhanced Write Inhibit Method

IP.com Disclosure Number: IPCOM000117044D
Original Publication Date: 1995-Dec-01
Included in the Prior Art Database: 2005-Mar-31
Document File: 2 page(s) / 36K

Publishing Venue

IBM

Related People

Kowa, T: AUTHOR [+4]

Abstract

Disclosed is a method for write abort of a hard disk drive using a read/write head which has an offset between a read and write head element, such as Magnet Resistive head.

This text was extracted from an ASCII text file.
This is the abbreviated version, containing approximately 92% of the total text.

Enhanced Write Inhibit Method

      Disclosed is a method for write abort of a hard disk drive
using a read/write head which has an offset between a read and write
head element, such as Magnet Resistive head.

      By applying new write abort criteria to conventional write
abort method which has an inhibit position error criteria and an
inhibit velocity criteria, write inhibit works properly against
unexpected disturbance, and it is effective for data integrity and
product reliability.

      New abort criteria is calculated in every servo sector from
current position error P(n) and current velocity P(n)-P(n-1) in a
following manner ((a) and (b));
       (a).  Calculate.  predicted P(n+1) using P(n) and P(n-1)
             P(n+1) = P(n) + (P(n)-P(n-1))
             = 2*P(n) - P(n-1)...................(1)
       (b).  Calculate NextDelta = |P(n+1)-P(target)| ...(2)
       (c).  Compare NextDelta and New criteria
       If it exceeds,then write abort.
       thus
       if NextDelta > New criteria ....(3)
       | ABORT
       endif
       where P(n)..  Position at servo sector n
       P(n+1)..  Predicted position at next sector n+1
       P(target) Target position

      Microprocessor always monitors the values given by equation (1)
and (2).  If the result of (2) exceeds the criteria, drive aborts
current write operation (3).  An actual abort case is shown in...