Intel Corporation
Circuits And Methods For Configurable Scan Chains

Abstract:

An integrated circuit includes first and second data storage circuits, first, second, and third shadow storage circuits, and first, second, and third multiplexer circuits. The first multiplexer circuit is configurable to provide a state of a data signal from the first data storage circuit to the first shadow storage circuit in a snapshot mode. The second multiplexer circuit is coupled between an output of the second data storage circuit and an input of the second shadow storage circuit. The third multiplexer circuit is coupled to the second multiplexer circuit. The third multiplexer circuit is configurable to provide a state of an output signal of the first shadow storage circuit to an input of the third shadow storage circuit in a scan mode bypassing the second shadow storage circuit.