Browse Prior Art Database

Circuit Performance Determination via Learning

IP.com Disclosure Number: IPCOM000103753D
Original Publication Date: 1993-Jan-01
Included in the Prior Art Database: 2005-Mar-18
Document File: 1 page(s) / 54K

Publishing Venue

IBM

Related People

McWilliam, B: AUTHOR [+3]

Abstract

Disclosed is a method for reducing the tester time needed to establish the speed at which an integrated circuit can perform. This is accomplished by taking advantage of the fact that adjacent integrated circuits typically display extremely similar performance characteristics. Thus, once the performance of a single device is established, this result can be used as an initial assessment point for surrounding devices.

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Circuit Performance Determination via Learning

      Disclosed is a method for reducing the tester time needed to
establish the speed at which an integrated circuit can perform.  This
is accomplished by taking advantage of the fact that adjacent
integrated circuits typically display extremely similar performance
characteristics.  Thus, once the performance of a single device is
established, this result can be used as an initial assessment point
for surrounding devices.

      The objective is to find that boundary between passing and
failing performance.  Thus, at a minimum, two tests are required, one
which passes, and another one step away which fails.  The solution
then is to learn the observed performance given one set of
environmental parameters (Vdd and temperature), and use this
information as the starting point for testing the next chip.  If this
test passes, the timing conditions are successively tightened until
the device under test fails.  If on the other hand, this first test
fails, the test is loosened successively until it passes.
Specifically, the algorithm is:
1.  Establish starting state.  If this is the first test under these
conditions, start at the specification limit.  Otherwise, use the
passing results from the previous device tested under these
conditions (power supply and temperature).
2.  Test the device using the starting state.  If it passes, go to
step 3.  Otherwise (fails first step), increase timing by one step.
If this exce...