Imaging activity in integrated circuits

The need to detect and localize activity exists in a variety of fields and has broad applications ranging from brain activity for neuroscience to image/video change detection for scene surveillance. In this paper, we introduce a method for localizing activity in integrated circuits (IC) using a laser scanning microscope. Specifically, we develop an activity measure using the Generalized Likelihood Ratio Test (GLRT) framework to detect if an electronic waveform is present at a laser scan location while a test program is repeatedly run. By plotting the activity score against laser scan location, an activity image is developed showing the measured activity in different parts of the IC. We show that this technique allows detection of all active regions in an operating IC, while requiring a relatively low number of signal acquisitions.