Although triple modular redundancy (TMR) has been widely used to mitigate single event upsets (SEUs) in static random access memory-based field-programmable gate arrays (FPGAs), SEU-caused bridging faults between the triplicated modules do not guarantee the correctness of TMR designs under all SEUs. In this paper, we present a novel computer-aided design flow for redundancy-based applications on FPGAs in order to mitigate the impact of SEUs in the configuration bitstreams. We introduce the notions of modular redundancy conflicts and vulnerability-gap conflicts which maintain the fundamental assumption underlying the integrity of redundancy-based designs (i.e., self-containment of SEU-induced faults within a single replica of redundant resources). When the impact of SEU-induced bridging faults is considered in high-level synthesis as well as physical synthesis, on average more than 30% improvement in the number of potential SEU-induced bridging faults can be reached as well as improvements in the performance and area utilization, compared to post-synthesis TMR, in which the voters are applied to the feedback structures in the circuit. Compared to the extreme case of post-synthesis TMR in which the voters are applied at the end of every configurable logic block, we reach 38% (26%) improvement in performance(area) of the implemented circuits.

Recent studies show that peripheral circuit (including decoders, wordline drivers, input and output drivers) constitutes a large portion of the cache leakage. In addition, as technology migrates to smaller geometries, leakage contribution to total power consumption increases faster than dynamic power, indicating that leakage will be a major contributor to overall power consumption. This paper presents zig-zag share, a circuit technique to reduce leakage in SRAM peripherals by putting them into low-leakage power sleep mode. The zig-zag share circuit is further extended to enable multiple sleep modes for cache peripherals. Each mode represents a trade-off between leakage reduction and the wakeup delay. Using architectural control of multiple sleep modes, an integrated technique called MSleep-Share is proposed and applied in L1 and L2 caches. MSleep-share relies on cache miss information to guide leakage control mechanism and switch peripheral circuit's power mode. The results show leakage reduction by up to 40× in deeply pipelined SRAM peripheral circuits, with small area overhead and small additional delay. This noticeable leakage reduction translates to up to 85% overall leakage reduction in on-chip memories.

In this paper, a novel thermal-aware dynamic placement planner for reconfigurable systems is presented, which targets transient temperature reduction. Rather than solving time-consuming differential equations to obtain the hotspots, we propose a fast and accurate heuristic model based on power budgeting to plan the dynamic placements of the design statically, while considering the boundary conditions. Based on our heuristic model, we have developed a fast optimization technique to plan the dynamic placements at design time. Our results indicate that our technique is two orders of magnitude faster while the quality of the placements generated in terms of temperature and interconnection overhead is the same, if not better, compared to the thermal-aware placement techniques which perform thermal simulations inside the search engine.

Although Triple Modular Redundancy (TMR) has been widely used to mitigate single event upsets (SEUs) in SRAM-based FPGAs, SEU-caused bridging faults between the TMR modules do not guarantee correctness of TMR design under SEU. In this paper, we present a novel approximation algorithm for resource binding on scheduled datapaths at the presence of TMR, which aims at containment of each SEU within a single replica of tripled operations. The key challenges are to avoid resource sharing between modular redundant operations and also to reduce the possibility of TMR masking breaches in resource allocation. We introduce the notion of vulnerability gap during resource sharing to potentially reduce the effort for white space allocation at the physical design stage in order to avoid bridging faults between TMR resources. The experimental results show that our proposed resource binding algorithm, followed by floorplanner, reduces the potential of TMR breaches by 20%, on average.

The majority of configuration bits affecting a design are devoted to FPGA routing configuration. We present a SEU-aware routing algorithm that provides significant reduction in bridging faults caused by SEUs. Depending on the routing architecture switches, for MCNC benchmarks, the number of care bits can be reduced between 13% and 19% on average with comparable delay. In addition, in Asymmetric SRAM FPGA using our router average FIT (failure-in-time) rate is reduced by 36%.