On-Chip Codeword Generation to Cope With Crosstalk

Abstract

Capacitive and inductive coupling between bus lines results in crosstalk induced delays. Many bus encoding techniques have been proposed to improve the performance. Existing implementation techniques and mapping algorithms in the literature only apply the specific encoding. This paper presents the first generalized framework for a stall-free on-chip codeword generation strategy that is scalable and easy to automate. It is applicable to the coupling aware encoding techniques that allow recursive codeword generation. The proposed implementation strategy iteratively generates codewords without explicitly enumerating them. Codeword mapping relies on graph-based representation that is unique to the given encoding technique. The codewords are calculated on-chip using basic function blocks, such as adders and multiplexers. Three encoding techniques were implemented using the proposed strategy. Experimental results show significant reduction in the area overhead and power dissipation over the existing method that uses random logic to implement the codec.