FAAR: A router for field-programmable analog arrays

Abstract

In this paper we address the routability and analog performance issues involved in routing for array-based FPAAs that have single-segment horizontal and vertical routing resources. We then present FAAR (field-programmable analog array router) and describe a routing algorithm developed for the target array-based FPAA architecture. Sequential routing technique is used for routing multi-terminal nets as well as multiple nets. Multi-terminal nets are broken into two-terminal pairs and routed. We use the notion of resource demand as a measure of the effect of a net-route on the routing of the other nets, while the number of programmable switches and the net-crossings are used as the metrics of interconnect parasitics. We present experiments to study the effect of various parameters such as the number of nets, terminals, CABs and I/O cells on the routing as well as the performance degradation. FAAR routes with high efficiency while keeping performance degradation small, and has considerably short execution times.