Adv Antest Corporation

Globalfoundries Inc.

Markus Seuring

Jochen Rivoir

Kay Hesse

Michael Braun

Kai Eichhorn

A test apparatus for generating reference scan chain test data comprises a test pattern generator and an output data modifier. The test pattern generator modifies a scan chain test input bit sequence by replacing a predefined number of start bits of the scan chain test input bit sequence by a predefined start bit sequence. Further, the test pattern generator provides the modified scan chain test input bit sequence to a device under test. The output data modifier modifies a scan chain test output bit sequence received from the device under test and caused by the modified scan chain test input bit sequence. The scan chain test output bit sequence is modified by replacing a predefined number of end bits of the scan chain test output bit sequence by a predefined end bit sequence to obtain the reference scan chain test data.

Test apparatus for generating reference scan chain test data and test system

An apparatus for determining a number of successive equal bits preceding an edge within a bit stream including a repetitive bit sequence includes an edge number determiner, an edge selector, a time stamper and an equal bits determiner. The edge number determiner determines a preset number of edges. The preset number of edges is coprime to a number of edges of the repetitive bit sequence or coprime to a maximal number of edges of the repetitive bit sequence. The edge selector selects edges of the bit stream spaced apart from each other by the preset number of edges. Further, the time stamper determines a time stamp for each selected edge of the bit stream and the equal bits determiner determines the number of successive equal bits preceding the edge based on determined time stamps of selected edges.

Apparatus for determining a number of successive equal bits preceding an edge within a bit stream and apparatus for reconstructing a repetitive bit sequence

In a sophisticated semiconductor device including a large memory portion, a built-in self-test circuitry comprises a failure capturing logic that allows the capturing of a bitmap at a given instant in time without being limited to specific operating conditions in view of interfacing with external test equipment. Thus, although pipeline processing may be required due to the high speed operation during the self-test, reliable capturing of the bitmap may be achieved while maintaining high fault coverage of the test algorithm under consideration.

Growing community of inventors

Stuttgart, Germany

Markus Seuring