Reducing structural bias in technology mapping

Technology mapping based on DAG-covering suffers from the problem of structural bias: the structure of the mapped netlist depends strongly on the subject graph. In this paper we present a new mapper aimed at mitigating structural bias. It is based on a simplified cut-based boolean matching algorithm, and using the speed afforded by this simplification we explore two ideas to reduce structural bias. The first, called lossless synthesis, leverages recent advances in structure-based combinational equivalence checking to combine the different networks seen during technology independent synthesis into a single network with choices in a scalable manner. We show how cut-based mapping extends naturally to handle such networks with choices. The second idea is to combine several library gates into a single gate (called a supergate) in order to make the matching process less local. We show how supergates help address the structural bias problem, and how they fit naturally into the cut-bas...

• Type: Conference
• Year: 2005
• Where: ICCAD
• Authors: Satrajit Chatterjee, Alan Mishchenko, Robert K. Brayton, Xinning Wang, Timothy Kam
• Keywords: Boolean Matching Algorithm, Hardware, ICCAD 2005, Structural Bias, Structural Bias Problem