Autonomous Multicycle Tests With Low Storage and Test Application Time Overheads
Irith Pomeranz · IEEE Transactions on Computer-Aided Design of Integrated Circuits and Systems · 2017
This paper defines a new type of multicycle tests called autonomous multicycle tests. Similar to multicycle scan-based tests, autonomous multicycle tests include several consecutive functional capture cycles to enhance defect detection and achieve test compaction. Unlike multicycle scan-based tests, an autonomous multicycle test set uses the same initial state for all the tests. During the functional capture cycles of a test, the primary inputs are driven by primary outputs, and the circuit operates autonomously. A test uses a scan-in operation only for the initial primary input vector, and to determine the connection between the primary inputs and outputs. It uses a scan-out operation only for the final primary output vector. This results in reduced overheads related to storage requirements and test application time compared with scan-based tests, and several unique properties that are discussed in this paper. This paper describes a test generation procedure for autonomous multicycle tests that avoids sequential test generation, and presents experimental results to demonstrate the ability of the tests to detect target faults.