International Business Machines Corporation

John James Shushereba

Franco Motika

Donato Orazio Forlenza

Phillip J Nigh

Phil Nigh

Ernest H Millham

John J Moser, Jr

Stephen V Pateras

Gary P Visco

A built-in stress circuit for an integrated circuit that has a frequency generator, at least one self-test circuit, a temperature regulator and a controller is disclosed. The frequency generator receives a reference clock and an adjusted temperature frequency from the temperature regulator and outputs the test frequencies needed for the self-test circuits. The self-test circuits, which are coupled to the frequency generator, receive the test frequencies and dissipate power as the self-test circuits are being used. The temperature regulator, which is coupled to the self-test circuits and the frequency generator, senses the power dissipated (i.e., the temperature), adjusts a temperature frequency corresponding to the temperature desired, and outputs the adjusted temperature frequency. The controller, which is coupled to the frequency generator, the self-test circuits, and the temperature regulator, provides the control data necessary for testing both electrical and thermal stress conditions.

Built-in dynamic stress for integrated circuits

An integrated circuit comprising logic circuits and self-test circuits for testing logic circuits including a pseudo random pattern generator for generating at least one pseudo random pattern and weighing circuit for weighing the pseudo random pattern. The weighting circuit and pseudo random pattern generator generate a plurality of weighted pseudo random patterns including at least one pair of a first weighted pseudo random pattern and a second weighted pseudo random pattern that is the complement of the first pattern. A weighting instruction selects one of the first or second pseudo random patterns for testing the logic circuits.

Weighted random pattern built-in self-test

A system and method for diagnosing the faults of an electronic device by running a series of tests, identifying the tests where the electronic device failed, without having to check the results of each test, storing information generated during only the tests where the electronic device failed, and using the information to diagnose the faults in the electronic device. The test results are accumulated into a Multiple Input Shift Register (MISR) which need not be examined after each test to determine which tests the device failed. The problem of a failure during one test manifesting into the MISR during subsequent tests is handled by predicting the effect of the failure on the MISR during subsequent tests.

Logic built in self-test diagnostic method

Apparatus for applying for a plurality of test cycles data specifying a plurality of test conditions to a multiple pin electronic circuit. A random access memory includes at a plurality of higher order addresses a complete data field for a plurality of test cycles. Some of said data fields include an operational code indicating that a minority of data bits in a field are to change in a consecutive number of following test cycles. A hold register is connected to receive each addressed row of test data from the memory. The higher order addresses of a memory addressed to produce complete data fields in the hold register. An operational code will be decoded to indicate a number of subsequent consecutive test cycles where a minority of data in the hold register are to be changed. The lower order addresses of the memory are subsequently addressed for a number of consecutive test cycles indicated by the operational code. The data contained in the lower order memory addresses is inserted in the hold register without changing the contents of a majority of hold register data bits.

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Essex Junction, VT, United States of America

John James Shushereba