CAREER: Analog-Assisted Sensing and Repair for Achieving Robust Near-Threshold Computing

patrick Chiang，俄勒冈州立大学职业：模拟辅助传感和修复实现稳健的近阈值计算智力优势：该职业提案的目标是探索模拟/混合信号传感电路和系统，使过程鲁棒计算在近阈值状态下运行。亚/近阈值计算，其中电源电压积极缩放到接近阈值电压，已被证明可以提高大约一个数量级的能源效率，但由于两个关键限制，对于大多数研究和商业应用来说是不可行的。首先，接近阈值的操作可能表现出非常大的进程变化延迟，从而导致不可预测的性能和吞吐量。其次，为了补偿时钟频率的降低，需要增加在近阈值下运行的并行核的数量。其结果是更依赖于连接这些多核的低功耗片上互连。因此，用于近阈值操作的低压摆幅片上互连是必不可少的，但这些降低的信号幅度水平会显著降低误码率。先前用于对抗过度延迟变化的技术，如剃刀式错误检测序列，不适用于在近阈值中观察到的预期的10倍延迟扩展。我们提出了一种新的完井检测器，使用模拟感测计算中消耗的电流，检测亚/近阈值延迟，与传统技术相比，在功率，面积和吞吐量方面有显着改善。我们将在这种模拟辅助传感的基础上，然后探索半异步流水线的优点。对于在近阈值下工作的片上互连，我们建议对这些并行低摆幅收发器进行模拟传感，定期监测和评估误码率。将研究近阈值操作加剧的过程非理想性的现场测量和校准，提供优化片上链路可靠性和功耗之间权衡的能力。更广泛的影响：提议的研究有望通过为下一代能源优化计算平台的设计奠定基础，从而影响相关的学术界、工业界和整个社会。应用包括能源受限的医疗设备，在这些设备中，以最小的消耗功率实现可靠的性能对于提高电池尺寸和使用寿命至关重要。此外，我们对近能量优化设计和延迟变化弹性架构中未探索问题的基础研究为降低芯片测试和设计验证的成本开辟了新的途径。教育目标将是增加工程专业少数民族本科生/研究生的入学率和保留率，并将新发现的研究创新直接应用于课程。此外，该提案促进了低功耗、近阈值原型的设计和制造方面的国际合作。通过为美国学生，特别是少数族裔学生提供与国际同事一起工作的机会，该提案将为美国工程专业学生提供未来全球化工作场所所需的领导素质。

ECCS-1151225Patrick Chiang, Oregon State UniversityCAREER: Analog-Assisted Sensing and Repair for Achieving Robust Near-Threshold ComputingIntellectual Merit: The goal of this CAREER proposal is to explore analog/mixed-signal sensing circuits and systems that will enable process-robust computing operating in the near-threshold regime. Sub/near-threshold computing, where the supply voltage is aggressively scaled to near the threshold voltage, has been shown to improve energy-efficiency by approximately an order of magnitude, but is not viable for most research and commercial applications due to two critical limitations. First, near-threshold operation can exhibit exceedingly large, process-varying delays, leading to unpredictable performance and throughput. Second, an increase in the number of parallel cores operating in near-threshold is required in order to compensate for the reduction in clock frequency. The result is a greater dependence on the low-power on-chip interconnect that connects these multiple cores. Low-voltage swing on-chip interconnect for near-threshold operation are therefore essential, but these reduced signal amplitude levels can significantly impair bit-error rates. Previous techniques to combat the excessive delay variations, such as Razor-like error detection sequentials, are unsuitable for the expected 10x delay spreads observed in near-threshold. We propose a new completion detector using analog sensing of the current consumed in computation, detecting sub/near-threshold delays with significant improvements in power, area, and throughput over conventional techniques. We will build upon this analog-assisted sensing by then exploring the merits of semi-asynchronous pipelining. For on-chip interconnects operating in near-threshold, we propose analog sensing of these parallel low-swing transceivers, periodically monitoring and assessing the bit-error rate. In-situ measurement and calibration of process non-idealities exacerbated by near-threshold operation will be investigated, providing the ability to optimize the trade-offs between on-chip link reliability and power consumption.Broader Impacts: The proposed research promises to impact related academia, industry, and society at large by laying the groundwork for the design of next generation, energy-optimal computing platforms. Applications include energy-constrained medical devices, where reliable performance at minimal consumed power is critical in order to improve battery size and lifetime. Furthermore, our fundamental research into unexplored problems in near-energy-optimal design and delay-variation resilient architectures opens new avenues for reducing the cost of chip testing and design verification. The education goals will be to increase enrollment and retention of minority undergraduate/graduate students in engineering, and apply the newly discovered research innovations directly to the curriculum. Furthermore, this proposal promotes international collaboration in the design and fabrication of low-power, near-threshold prototypes. By providing US students, especially minority students, the opportunity to work first-hand with international colleagues, this proposal will furnish US engineering students with the leadership qualities necessary for the future globalized workplace.