When IR-drop in LSI testing becomes excessive in a certain area of LSI, it causes excessive delay, resulting in test malfunction (over-testing). This is because power consumption in the test mode is generally much higher than in the normal mode. Excessive IR-drop does not occur in the entire area of a circuit, but in certain areas where a large number of switching activities occur (such areas are called hotspots in this work). In order to avoid test malfunction, it is important to develop a method to reduce or control IR-drop in the hotspots. Locating hotspots is a necessary technique to reduce or control IR-drop effectively and efficiently. In this work, we propose a method to locate hotspots caused in the test mode by switching probability calculation and functional analysis with partial truth table. Experimental results for IWLS2005 OpenCores circuits demonstrate the proposed method can support to locate hotspots.
OGATA et al. (Thu,) studied this question.