Fine-Grained Interconnect Synthesis

Abstract

One of the key challenges for the FPGA industry going forward is to make the task of designing hardware easier. A significant portion of that design task is the creation of the interconnect pathways between functional structures. We present a synthesis tool that automates this process and focuses on the interconnect needs in the fine-grained (sub-IP-block) design space. Here there are several issues that prior research and tools do not address well: the need to have fixed, deterministic latency between communicating units (to enable high-performance local communication without the area overheads of latency-insensitivity), and the ability to avoid generating un-necessary arbitration hardware when the application design can avoid it. Using a design example, our tool generates interconnect that requires 72% fewer lines of specification code than a hand-written Verilog implementation, which is a 33% overall reduction for the entire application. The resulting system, while requiring 4% more total functional and interconnect area, achieves the same performance. We also show a quantitative and qualitative advantages against an existing commercial interconnect synthesis tool, over which we achieve a 25% performance advantage and 17%/57% logic/memory area savings.