Modeling Switching Activity Using Cascaded Bayesian Networks for Correlated Input Streams

We represent switching activity in VLSI circuits using a graphical probabilistic model based on Cascaded Bayesian Networks (CBN’s). We develop an elegant method for maintaining probabilistic consistency in the interfacing boundaries across the CBN’s during the inference process using a tree-dependent (TD) probability distribution function. A tree-dependent (TD) distribution is an approximation of the true joint probability function over the switching variables, with the constraint that the underlying Bayesian network representation is a tree. The tree approximation of the true joint probability function can be arrived at using a Maximum Weight Spanning Tree (MWST) built using pairwise mutual information between switchings at two signal lines. Further, we also develop a TD distribution based method to model correlations among the primary inputs which is critical for accuracy in Bayesian modeling of switching activity. Experimental results for ISCAS circuits are presented to illustr...

• Type: Conference
• Year: 2002
• Where: ICCD
• Authors: Sanjukta Bhanja, N. Ranganathan
• Keywords: Hardware, ICCD 2002, Joint Probability Function, Probability Distribution Function, True Joint Probability