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Browse Prior Art Database

Method to Read Dipswitches From Multiple Card Levels

IP.com Disclosure Number: IPCOM000119399D
Original Publication Date: 1991-Jan-01
Included in the Prior Art Database: 2005-Apr-01
Document File: 1 page(s) / 37K

Publishing Venue

IBM

Related People

Eby, KE: AUTHOR

Abstract

Disclosed is a method for a single code version to read dipswitches from multiple card levels in order to reduce code testing time and number of releases.

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

Method to Read Dipswitches From Multiple Card Levels

      Disclosed is a method for a single code version to read
dipswitches from multiple card levels in order to reduce code testing
time and number of releases.

      For this particular application there are eight settings that
need to be read from the dipswitches which are read in from four
input pins on an ASIC.  The V2 Card has the capability of selecting
three different banks of four dipswitches configured as shown in the
figure.  The V1 Card was not designed to select different banks so
the same four switches are read independent of the select lines.

      When all three banks are found to have the same value, the code
identifies the card as V1 or a V2 card with all switches off.  In
this case the first four settings are set to the value
(BANK1=BANK2=BANK3) and the second four settings set to off(0).
Because of the way that the V2 card is populated with dipswitches,
the only way all three banks can be the same is if all switches are
off(BANK3=0).

      If any one of the banks is different, the code identifies the
card as a V2 and sets the first four settings to the value (BANK1 XOR
BANK2) and the second four settings to the value (BANK3).  This can
be done with both configurations of the V2 card since the dipswitches
addressed at BANK1 cannot be populated in the same card that has
dipswitches addressed at BANK2 and vice versa.  In Configuration #2,
the value read from BANK3 is always 0.