New design methodology with efficient prediction of quality metrics for logic level design towards dynamic reconfigurable logic

Abstract

The importance of efficient area and timing estimation is well established in high level synthesis (HLS) since it allows more efficient exploration of the design space while providing HLS tools with the capability of predicting the effects of technology specific tools on the design space. Much of the previous work has focused on estimation techniques that use very simple cost models based solely on functional units (FUs). Those models are not accurate enough to allow effective design space exploration since the effects of interconnects can indeed dominate the final design cost. The situation becomes even worst when the design is targeted to dynamically reconfigurable logic (DRL) technologies since the multiplexer delay may contribute heavily on the overall delay. In addition, large number of configurable logic blocks could be used for communication rather than for implementing FUs. In this paper we Present a new HLS design flow, which performs an accurate estimation on area and timing for DRL circuits. It takes into account not only FUs area and delay, but also the interconnection and communication effects. We select our DRL LSI circuit [M. Meribout, M. Motomura, Method for compiling high level programs into hardware, Japanese Patent: JSP2000-313818, 2000; M. Motomura et al., An embedded DRAM-FPGA chip with instantaneous logic reconfiguration, in: Symposium on VLSI Circuits, July 1997, pp. 55-56] as our main concentration. We tested our method with several benchmarks and the results show that we receive good performance of the design, with area and timing estimated efficiently.