Transition delay detector for interconnect test

Abstract

A test circuitry is configured to test for transition delay defects in a first inter-die interconnect connecting a first die and a second die. A test data value is initially received and temporarily stored in a data storage element. The test data is subsequently looped between the storage element and the second die through a feedback loop including the first inter-die interconnect and a second inter-die interconnect. A data conditioner conditions the test data value received from the second die so as to make it distinguishable from the test data value sent to the second die. A clock pulse generator generates a delayed clock pulse. A selection logic applies the generated delayed clock pulse and the conditioned fed back test data value to the data storage element. A readout unit for reading out a test data value stored in the data storage element.