Micron Technology Incorporated

Gregory L Cowan

Roland Ochoa

Kim M Pierce

Fariborz F Roohparvar

Mark A Hawes

Allahyar Vahidi Mowlavi

A semiconductor integrated circuit and method for compressing test stimuli to one test output signal during a test mode. The test output signal is driven from one input/output node of the semiconductor integrated circuit to a test station through a load board interface. Buffer circuitry on the semiconductor integrated circuit drive a high impedance to the input/output nodes of the integrated circuit during the test mode. The load board interface allows a single test station to receive test output signals from a plurality of semiconductor integrated circuits of the invention during the test mode, thereby allowing one test station to simultaneously test a plurality of circuits.

Semiconductor integrated circuit having compression circuitry for compressing test data, and the test system for utilizing the semiconductor integrated circuit

Semiconductor integrated circuit having compression circuitry for compressing test data, and the test system and method for utilizing the semiconductor integrated circuit

A memory system operable in a normal mode of operation and a test mode of operation includes sensing circuitry which generates x number of data bits during a read cycle. A read path circuit, coupled to the sensing circuitry, transfers the x number of data bits generated by the sensing circuitry during a first read cycle in the normal mode of operation to x number of output nodes. A first detection circuit, coupled to the read path circuit, detects whether or not the x number of data bits generated by the sensing circuitry during a second read cycle in the test mode of operation are arranged in a pattern in which all bits are identical. A second detection circuit, coupled to the read path circuit, detects whether or not the x number of data bits generated by the sensing circuitry during the second read cycle in the test mode of operation are arranged in a pattern in which each two adjacent bits are different. An output circuit, coupled to the first and second detection circuits, generates y number of output data bits which are arranged in a pattern indicative of whether the x number of data bits generated by the sensing circuitry during the second read cycle in the test mode of operation are identical, are arranged in a pattern in which each two adjacent bits are different, or are arranged in another pattern, and wherein y is less than x. A method of testing an integrated circuit (IC) memory is also disclosed.

Output data compression scheme for use in testing IC memories

Semiconductor integrated circuit having compression circuitry for

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Boise, ID, United States of America

Gregory L Cowan