Facilitating FPGA Reconfiguration through Low-level Manipulation

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Virginia Tech


The process of FPGA reconfiguration is to recompile a design and then update the FPGA configuration correspondingly. Traditionally, FPGA design compilation follows the way how hardware is compiled for achieving high performance, which requires a long computation time. How to efficiently compile a design becomes the bottleneck for FPGA reconfiguration.

It is promising to apply some techniques or concepts from software to facilitate FPGA reconfiguration. This dissertation explores such an idea by utilizing three types of low-level manipulation on FPGA logic and routing resources, i.e. relocating, mapping/placing, and routing. It implements an FMA technique for "fast reconfiguration". The FMA makes use of the software compilation technique of reusing pre-compiled libraries for explicitly reducing FPGA compilation time. Based the software concept of Autonomic Computing, this dissertation proposes to build an Autonomous Adaptive System (AAS) to achieve "self-reconfiguration". An AAS absorbs the computing complexity into itself and compiles the desired change on its own.

For routing, an FPGA router is developed. This router is able to route the MCNC benchmark circuits on five Xilinx devices within 0.35 ~ 49.05 seconds. Creating a routing-free sandbox with this router is 1.6 times faster than with OpenPR. The FMA uses relocating to load pre-compiled modules and uses routing to stitch the modules. It is an essential component of TFlow, which achieves 8 ~ 39 times speedup as compared to the traditional ISE flow on various test cases. The core part of an AAS is a lightweight embedded version of utilities for managing the system's hardware functionality. Two major utilities are mapping/placing and routing. This dissertation builds a proof-of-concept AAS with a universal UART transmitter. The system autonomously instantiates the circuit for generating the desired BAUD rate to adapt to the requirement of a remote UART receiver.



FPGA Reconfiguration, Bitstream-level Manipulation, FPGA Routing, Module Reuse, Design Assembly, Autonomous Adaptive Systems, Electronic Design Automation