Synthesizing Synchronous Elastic Flow Networks

This paper describes an implementation language and synthesis system for automatically generating latency insensitive synchronous digital designs. These designs decouple behavioral correctness from design performance by allowing any sub-component to dynamically stall without changing correct system activity. This is accomplished by imposition of global invariants and use of local control in the form of Synchronous-Elastic Flow (SELF) networks, which are directly synthesized. This design description format reduces the complexity of implementing correct SELF networks and does not require pre-design of a correct conventional synchronous design. The design description is a specialized guarded atomic action language which is particularly suited for succinctly describing SELF designs. We present the language syntax, semantics and synthesis techniques illustrated by the design of a latency tolerant cache controller.