Pulsed Laser SEU Cross Section Measurement Using Coincidence Detectors

Pulsed laser testing is a useful technique for an accurate inspection of potential weak zones in a layout of an integrated circuit. A laser pulse can provoke a similar effect as a particle hitting with the advantage of a perfect location of the hitting point. The present work describes a general method to determine a Pulsed Laser Single Event Upset (SEU) Cross Section over digital circuits by means of counting statistics. The technique is based on a coincidence detector that counts fault events by comparing synchronous outputs of the digital circuit under test and a replica of the design running on a control FPGA. A correspondence map, previously generated by injection fault analysis techniques on the replica, establishes a one-way correspondence between output patterns and each bit flip. With this scheme, the SEU is detected dynamically just using a comparison between the running model and the circuit.