Browse Prior Art Database

Status Check Method of Chipcard Expansion Unit

IP.com Disclosure Number: IPCOM000119131D
Original Publication Date: 1997-Dec-01
Included in the Prior Art Database: 2005-Apr-01
Document File: 4 page(s) / 83K

Publishing Venue

IBM

Related People

Ogura, A: AUTHOR [+3]

Abstract

Disclosed is a method for checking the status of an expansion unit, and disconnecting logical and electrical connections from the unit if it is not in proper status by utilizing the same mechanism that is used when the expansion unit is detached. ChipCard is a device in the form factor of a Personal Computer (PC) card, which functions as a very small computer when it stands alone, and functions as a slave PC card when it is inserted into an external (host) PC with which to interface. With the ChipCard expanded bus (*), the ChipCard can have an expansion card as its slave device into which the ChipCard can be accommodated.

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

Status Check Method of Chipcard Expansion Unit

      Disclosed is a method for checking the status of an expansion
unit, and disconnecting logical and electrical connections from the
unit if it is not in proper status by utilizing the same mechanism
that is used when the expansion unit is detached.  ChipCard is a
device in the  form factor of a Personal Computer (PC) card, which
functions as a very  small computer when it stands alone, and
functions as a slave PC card when it is inserted into an external
(host) PC with which to interface.  With the ChipCard expanded bus
(*), the ChipCard can have an  expansion card as its slave device
into which the ChipCard can be accommodated.

      Fig. 1(a) and (b) show the card insertion detecting mechanism
of a normal PC card and a host PC's PC card slot, respectively.  On
the ChipCard expanded bus system, -CD1 pin of the expansion unit
should be  routed to -CD2 pin, independent from any signal including
powers and ground.  Since the signal current runs from -CD1 to -CD2,
a diode can be inserted on this line.

      Fig. 1(c) and (d) show the detecting mechanism by which the
ChipCard can detect and verify the insertion into an expansion unit.
Status check logic is any kind of hardware whose output (EXP_READY)
goes high only if the expansion unit is working well.  Otherwise,
EXP_READY stays low.  EXP_READY is connected to -CD2  through a
diode, so that it consists of wired-OR with the input from -CD1 (Fig.
1(c)).

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