A time-multiplexed FPGA overlay with linear interconnect

Xiangwei Li, Abhishek Kumar Jain, Douglas L. Maskell, Suhaib A. Fahmy

Research output: Chapter in Book/Report/Conference proceedingConference contribution

9 Scopus citations


Coarse-grained overlays improve FPGA design productivity by providing fast compilation and software like programmability. Soft processor based overlays with well-defined ISAs are attractive to application developers due to their ease of use. However, these overlays have significant FPGA resource overheads. Time multiplexed (TM) CGRA-like overlays represent an interesting alternative as they are able to change their behavior on a cycle by cycle basis while the compute kernel executes. This reduces the FPGA resource needed, but at the cost of a higher initiation interval (II) and hence reduced throughput. The fully flexible routing network of current CGRA-like overlays results in high FPGA resource usage. However, many application kernels are acyclic and can be implemented using a much simpler linear feed-forward routing network. This paper examines a DSP block based TM overlay with linear interconnect where the overlay architecture takes account of the application kernels' characteristics and the underlying FPGA architecture, so as to minimize the II and the FPGA resource usage. We examine a number of architectural extensions to the DSP block based functional unit to improve the II, throughput and latency. The results show an average 70% reduction in II, with corresponding improvements in throughput and latency.
Original languageEnglish (US)
Title of host publicationProceedings of the 2018 Design, Automation and Test in Europe Conference and Exhibition, DATE 2018
PublisherInstitute of Electrical and Electronics Engineers Inc.
Number of pages6
ISBN (Print)9783981926316
StatePublished - Apr 19 2018
Externally publishedYes

Bibliographical note

Generated from Scopus record by KAUST IRTS on 2021-03-16


Dive into the research topics of 'A time-multiplexed FPGA overlay with linear interconnect'. Together they form a unique fingerprint.

Cite this