Browse Prior Art Database

Logging POWER Cycles and Hours

IP.com Disclosure Number: IPCOM000099307D
Original Publication Date: 1990-Jan-01
Included in the Prior Art Database: 2005-Mar-14
Document File: 2 page(s) / 74K

Publishing Venue

IBM

Related People

Kerchberger, SW: AUTHOR [+2]

Abstract

A microprocessor in an intelligent direct access device (DASD) keeps track of power cycles and hours. The information is preserved by recording in a reserved location on the DASD. The information is by reading the reserved location.

This text was extracted from an ASCII text file.
This is the abbreviated version, containing approximately 52% of the total text.

Logging POWER Cycles and Hours

       A microprocessor in an intelligent direct access device
(DASD) keeps track of power cycles and hours.  The information is
preserved by recording in a reserved location on the DASD.  The
information is by reading the reserved location.

      An intelligent file device controller keeps track of and power
cycles.  After power-up, microcode updates a cycles "meter."  After a
predetermined amount of time elapsed, the microcode updates a POH
(power-on hours)  The meters are counters stored on the DASD in a of
reserved area.  The reserved area is not used for customer data and
is typically not accessible by the system.  The amount of time
between updates of the is relatively large so as not to impact file

      POWER CYCLES:  Power-on reset microcode (i.e., code from ROS
when a file is first powered on) sets a to indicate power has been
cycled.  Later, in the file microcode, after the file has been
spun-up optionally microcode loaded from the reserved area), last
function of the initialization microcode is to read sector from the
reserved area that contains the meters. the flag described above is
set, then increment the power meter.  Write the sector back to the
reserved area clear the flag.

      POWER-ON HOURS:  During initialization, a timer routine set up.
 A typical timer routine involves the following: hardware down
counter capable of being set by microcode to a predetermined value.
The decrements based on a fixed frequency.  The frequency is the
microprocessor oscillator or other fixed time interval event (such as
a disk index pulse).  The executes instructions while the decrements.
 Both occur simul...