Reducing energy by exploring heterogeneity in a coarse-grain fabric

This paper explores the impact of heterogeneity on energy consumption in a stripe-based coarse-grain fabric architecture. We examine the benefit of replacing 25-50% of functional blocks with dedicated vertical routes in the fabric. Additionally, we reduce the number of operations supported by the functional units from 23 to 16, 10 and 8. To assist in testing and examining the impact of these different architectures on energy consumption, an automation process was created to automatically generate fabric instances based on a fabric instance model (FIM) written in XML. The FIM is also used as an input parameter to our heuristic mapper in order to program a particular fabric instance. Upon testing these instances, we found that the fabric with ALUs supporting 10-operations and using an 8:1 interconnect with 33% of the functional units replaced with dedicated pass gates provided the best energy versus mappability tradeoff, resulting in a 32% energy improvement and a 47% area savings over the baseline fabric with ALUs supporting 23-operations and using an 8:1 interconnect without dedicated vertical routes.