Hewlett-packard Company

Matthew L Snook

William A Groves

Rodney Browen

John E McDermid

William J Nicolay

A circuit tester and test technique are presented that compresses the amount of data stored in local test data RAMs for the implementation of a circuit test, thereby reducing the amount of data that must be downloaded to the local test data RAMs, thereby improving test throughput. Derivative data vectors are utilized in addition to raw data vectors as part of the data compression technique. Further compression results from storing only unique data vectors in the local test data RAMs and utilizing a sequencer to control the order in which the unique data vectors are utilized. The sequencer includes test program logic and logic capable of implementing on test pins indirect counters.

Circuit testing utilizing data compression and derivative mode vectors

Circuit tester having on-the-fly comparison of actual and expected

Circuit tester having indirect counters

An apparatus and a method is provided for verifying electrical coupling between a first contact point of an electrical device on a circuit board and a first connection pin, on a board tester. Within the tester, a JK flip-flop is electrically coupled to the first connection pin through an amplifier. A Q output of the JK flip-flop is initialized to a logic 0. An electrical probe with an electrical voltage is stroked across the first contact point and any other contact points on the circuit. If the first contact point is electrically coupled to the first connection pin, a logic 1 will be held on the Q output of the JK flip-flop. If there is no electrical coupling, then a logic 0 will be held on the Q output. By reinitializing the JK flip-flop and electrically coupling it to another connection pin, electrical coupling between another contact point and another connection pin may be tested.

Connection verification between circuit board and circuit tester

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Loveland, CO, United States of America

Matthew L Snook