Browse Prior Art Database

Actuator Control Circuit for Small Hard Drive Disk

IP.com Disclosure Number: IPCOM000111125D
Original Publication Date: 1994-Feb-01
Included in the Prior Art Database: 2005-Mar-26
Document File: 2 page(s) / 49K

Publishing Venue

IBM

Related People

Kigami, Y: AUTHOR [+2]

Abstract

Disclosed is a Hard Disk Drive System which provides effective control of a hard disk having high density embedded sector servo patterns. By adding a circuit for controlling the actuator , a local CPU can processes the other jobs, then HDD can respond to the host command quickly, even if the system has only one CPU.

This text was extracted from an ASCII text file.
This is the abbreviated version, containing approximately 85% of the total text.

Actuator Control Circuit for Small Hard Drive Disk

      Disclosed is a Hard Disk Drive System which provides effective
control of a hard disk having high density embedded sector servo
patterns.  By adding a circuit for controlling the actuator , a local
CPU can processes the other jobs, then HDD can respond to the host
command quickly, even if the system has only one CPU.

      In a conventional Hard Disk Drive system, a local CPU controls
the position of a head by analyzing position error information from
the servo pattern.  For controlling such disks having embedded sector
servo patterns, which is conventionally used in small HDD, the local
CPU has to execute this "Servo job" in every servo sector.  But the
local CPU has to execute some other jobs such as;

 - Response to the host command.  = "Host job"

 - Control the HDC(Hard disk controller).  = "HDC job"

 - etc.

The processing time of the local CPU is shared by some jobs (Fig. 1).

      Recently, the number of the servo sectors in one revolution is
being increased for getting more accuracy, speed and stiffness of the
positioning of the head.  So the local CPU has to spend much time to
execute the "Servo job".  Then the local CPU can not spend sufficient
time for processing the other jobs and it results in slow response
and low performance of the HDD.  This problem can be solved by adding
another CPU, but it is expensive.

      As shown in Fig. 2, "HDC job" occures only when the actuator
fo...