Several recent processor designs have proposed to enhance performance by increasing the clock frequency to the point where timing faults occur, and by adding error-correcting support to guarantee correctness. However, such Timing Speculation (TS) proposals are limited in that they assume traditional design methodologies that are suboptimal under TS. In this paper, we present a new approach where the processor itself is designed from the ground up for TS. The idea is to identify and optimize the most frequently-exercised critical paths in the design, at the expense of the majority of the static critical paths, which are allowed to suffer timing errors. Our approach and design optimization algorithm are called BlueShift. We also introduce two techniques that, when applied under BlueShift, improve processor performance: On-demand Selective Biasing (OSB) and Path Constraint Tuning (PCT). Our evaluation with modules from the OpenSPARC T1 processor shows that, compared to conventional TS, BlueShift with OSB speeds up applications by an average of 8% while increasing the processor power by an average of 12%. Moreover, compared to a high-performance TS design, BlueShift with PCT speeds up applications by an average of 6% with an average processor power overhead of 23% -providing a way to speed up logic modules that is orthogonal to voltage scaling.

Hydrothermal treatment not only reduces the cost of moisture removal but also improves the quality of the syngas from steam gasification for sewage sludge. However, the effect of the treatment on the gasification behavior, including the reactivity and emission of gaseous N compounds, was not clear. In this study, the kinetic analysis based on a thermogravimetric (TG) experiment was used to examine the reactivity of the hydrochars. In addition, the evolution of N functionalities in hydrochar with treatment conditions and the discharge of NH 3 and HCN during gasification were also investigated. The result showed that the treatment lowered the activation energy of sludge in gasification of remaining char and effectively reduced the discharge of NH 3 and HCN. CaO addition into raw sludge before treatment caused the shift of the peak temperature to the lower range in remaining char gasification and promoted the conversion of HCN to NH 3 .

Abstract-In this paper, we present a low-power architectural synthesis system (LOPASS) for field-programmable gate-array (FPGA) designs with interconnect power estimation and optimization. LOPASS includes three major components: 1) a flexible high-level power estimator for FPGAs considering the power consumption of various FPGA logic components and interconnects; 2) a simulated-annealing optimization engine that carries out resource selection and allocation, scheduling, functional unit binding, register binding, and interconnection estimation simultaneously to reduce power effectively; and 3) a -cofamily-based register binding algorithm and an efficient port assignment algorithm that reduce interconnections in the data path through multiplexer optimization. The experimental results show that LOPASS produces promising results on latency optimization compared to an academic high-level synthesis tool SPARK. Compared to an early commercial high-level synthesis tool, namely, Synopsys Behavioral Compiler, LOPASS is 61.6% better on power consumption and 10.6% better on clock period on average. Compared to a current commercial tool, namely, Impulse C, LOPASS is 31.1% better on power reduction with an 11.8% penalty on clock period.Index Terms-Behavioral synthesis, field-programmable gate array (FPGA), interconnect, power optimization.

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We propose afast data relay(FDR) mechanism to enhance existing CGRA (coarse-grained reconfigurable architecture). FDR can not only provide multicycle data transmission in concurrent with computations but also convert resource-demanding inter-processing-element global data accesses into local data accesses to avoid communication congestion. We also propose the supporting compiler techniques that can efficiently utilize the FDR feature to achieve higher performance for a variety of applications. Our results on FDR-based CGRA are compared with two other works in this field: ADRES and RCP. Experimental results for various multimedia applications show that FDR combined with the new compiler deliver up to 29% and 21% higher performance than ADRES and RCP, respectively.