Credence Systems Corporation

Frederic Giral

Jean-Claude Fournel

Michael Frank Jones

William A Fritzsche

A test apparatus has multiple instruments that are synchronized with respect to one another so that a trigger signal may be generated in response to events occurring at different instruments. The events may correspond to events defined within a test program or events detected at a device under test. A partial trigger signal is generated by each of the different instruments, and the partial trigger signals are used in generating the trigger signal. Different offset delays are applied to the partial trigger signals so that the partial trigger signals generated by the different instruments are synchronized with respect to each other.

Synchronization of multiple test instruments

A test apparatus has multiple instruments that are synchronized with respect to one another so that test data generated by them arrive at the pins of a device under test at the time specified in a test program. The synchronization of the multiple instruments is carried out by introducing delays to triggers that are generated and used by the multiple instruments. The amount of delay that is introduced varies from instrument to instrument and is based on differences in the actual transmission and processing delays and clock rates.

Method and apparatus for circuit testing with ring-connected test instrument modules. A system for controlling one or more test instruments to test one or more integrated circuits includes a master clock and a controller. The test instruments are connected to form a communication ring. The master clock is connected to each test instrument and provides a clock signal to the one or more test instruments. The controller is connected to the communication ring and is configured to align counters of test instruments to derive a common clock time value from the clock signal. The controller is further configured to generate and send data words into the communication ring to carry the data words to each test instrument. The data words includes at least one data word specifying a test event to be performed, a common clock time value, and at least one of the test instruments.

Growing community of inventors

Pourcieux, France

Frederic Giral