FAAR: A Router for Field-Programmable Analog Arrays

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 IO 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.