Workload-Aware Static Aging Monitoring and Mitigation of Timing-Critical Flip-Flops
Workload-Aware Static Aging Monitoring and Mitigation of Timing-Critical Flip-Flops
复制标题
DOI：
10.1109/tcad.2017.2778254
复制
发表时间：
2018-10
影响因子：
2.9
通讯作者：
Arunkumar Vijayan;S. Kiamehr;Fabian Oboril;K. Chakrabarty;M. Tahoori
中科院分区：
文献类型：
--
作者：
Arunkumar Vijayan;S. Kiamehr;Fabian Oboril;K. Chakrabarty;M. Tahoori
在先进技术节点中，偏置温度不稳定性（BTI）已成为一个突出的可靠性问题。BTI的最坏情况影响发生在特定的工作负载阶段，其中关键路径上的触发器（FF）长时间不切换其逻辑值。电路中的这些非活动FF经历加速的工作负载依赖性静态BTI（S-BTI）应力。由于动态BTI，S-BTI几个小时的老化效果已被证明相当于一年的老化，最终可能导致电路故障。可用于在电路的待机模式期间减轻S-BTI应力的技术是悲观的，从而限制了电路的性能。为了解决这个问题，我们提出了一个运行时监控方法，提出了一个标志时，一个时间关键FF经历严重的S-BTI压力。为了降低监控成本，我们选择了一个小的代表性的FF离线工作负载感知相关性分析的基础上，这些选定的FF进行在线监测的静态老化阶段。我们在两个处理器上进行的实验表明，少于0.5%的FF的总数需要被选为代表FF的S-BTI压力监测。我们还提出了一个低开销的缓解方案，放松关键FF通过执行一个软件子程序，旨在行使关键FF。
In advanced technology nodes, bias temperature instability (BTI) has emerged as a prominent reliability concern. The worst-case effects of BTI occur during specific workload phases in which flip-flops (FFs) on a critical path do not switch their logic values for a long duration. These inactive FFs in the circuit experience accelerated workload-dependent static-BTI (S-BTI) stress. The aging effect of S-BTI for a few hours has been shown to be equivalent to one year of aging due to dynamic BTI, which can eventually cause circuit failure. The techniques available to mitigate S-BTI stress during standby mode of circuits are pessimistic, thereby limiting the performance of the circuit. To address this problem, we propose a runtime monitoring method to raise a flag when a timing-critical FF experiences severe S-BTI stress. To reduce the monitoring costs, we select a small representative set of FFs offline based on workload-aware correlation analysis and these selected FFs are monitored online for static aging phases. Our experiments conducted on two processors show that less than 0.5% of the total number of FFs is required to be selected as representative FFs for S-BTI stress monitoring. We also propose a low-overhead mitigation scheme to relax critical FFs by executing a software subroutine that is designed to exercise critical FFs.