{"title":"Systematic power reduction and performance analysis of mismatch limited ADC designs","authors":"P. Scholtens, D. Smola, M. Vertregt","doi":"10.1145/1077603.1077622","DOIUrl":"https://doi.org/10.1145/1077603.1077622","url":null,"abstract":"This paper focuses on several methods to save power consumption in mismatch limited ADC designs, like flash and folding architectures. Migrating existing designs to a next submicron technology helps to reduce the power consumption significantly. It is shown that decreasing bandwidth and sample rate creates a more than linear reduction of the power consumption. Both of these methods are addressed in this paper. Also the balance between power consumption of the analog and digital circuitry is examined. An existing 6-bit 1.6GS/s ADC in 0.18/spl mu/m CMOS is transferred to a 0.12/spl mu/m technology. The sampling rate is reduced to 260MS/s, the measured ERBW to 124MHz while running at only 32mW. As the bandwidth is downscaled 5/spl times/, the power consumption is reduced by 10/spl times/, which results in an improved conversion efficiency. As the design topology is unaltered, the implemented design sets a reference for evaluation of any low-power technique.","PeriodicalId":256018,"journal":{"name":"ISLPED '05. Proceedings of the 2005 International Symposium on Low Power Electronics and Design, 2005.","volume":"36 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2005-08-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115876700","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Energy-efficient and high-performance instruction fetch using a block-aware ISA","authors":"Ahmad Zmily, C. Kozyrakis","doi":"10.1145/1077603.1077614","DOIUrl":"https://doi.org/10.1145/1077603.1077614","url":null,"abstract":"The front-end in superscalar processors must deliver high application performance in an energy-effective manner. Impediments such as multi-cycle instruction accesses, instruction-cache misses, and mispredictions reduce performance by 48% and increase energy consumption by 21%. This paper presents a block-aware instruction set architecture (BLISS) that defines basic block descriptors in addition to the actual instructions in a program. BLISS allows for a decoupled front-end that reduces the time and energy spent on misspeculated instructions. It also allows for accurate instruction prefetching and energy efficient instruction access. A BLISS-based front-end leads to 14% IPC, 16% total energy, and 83% energy-delay-squared product improvements for wide-issue processors.","PeriodicalId":256018,"journal":{"name":"ISLPED '05. Proceedings of the 2005 International Symposium on Low Power Electronics and Design, 2005.","volume":"51 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2005-08-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130270746","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Peak temperature control and leakage reduction during binding in high level synthesis","authors":"R. Mukherjee, S. Memik, G. Memik","doi":"10.1145/1077603.1077663","DOIUrl":"https://doi.org/10.1145/1077603.1077663","url":null,"abstract":"Temperature is becoming a first rate design criterion in ASICs due to its negative impact on leakage power, reliability, performance, and packaging cost. Incorporating awareness of such lower level physical phenomenon in high level synthesis algorithms help to achieve better designs. In this work, we developed a temperature aware binding algorithm. Switching power of a module correlates with its operating temperature. The goal of our binding algorithm is to distribute the activity evenly across functional units. This approach avoids steep temperature differences between modules on a chip, hence, the occurrence of hot spots. Starting with a switching optimal binding solution, our algorithm iteratively minimizes the maximum temperature reached by the hottest functional unit. Our algorithm does not change the number of resources used in the original binding. We have used HotSpot, a temperature modeling tool, to simulate temperature of a number ASIC designs. Our binding algorithm reduces temperature reached by the hottest resource by 12.21/spl deg/C on average. Reducing the peak temperature has a positive impact on leakage as well. Our binding technique improves leakage power by 11.89%, and overall power by 3.32% on average at 130nm technology node compared to a switching optimal binding.","PeriodicalId":256018,"journal":{"name":"ISLPED '05. Proceedings of the 2005 International Symposium on Low Power Electronics and Design, 2005.","volume":"36 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2005-08-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134074791","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Instruction packing: reducing power and delay of the dynamic scheduling logic","authors":"J. Sharkey, D. Ponomarev, K. Ghose, O. Ergin","doi":"10.1145/1077603.1077613","DOIUrl":"https://doi.org/10.1145/1077603.1077613","url":null,"abstract":"The instruction scheduling logic used in modern superscalar microprocessors often relies on associative searching of the issue queue entries to dynamically wakeup instructions for the execution. Traditional designs use one issue queue entry for each instruction, regardless of the actual number of operands actively used in the wakeup process. In this paper we propose instruction packing - a novel microarchitectural technique that reduces both the delay and the power consumption of the issue queue by sharing the associative part of an issue queue entry between two instructions, each with at most one nonready register source operand at the time of dispatch. Our results show that instruction packing provides a 39% reduction of the whole issue queue power and 21.6% reduction in the wakeup delay with as little as 0.4% IPC degradation on the average across the simulated SPEC benchmarks.","PeriodicalId":256018,"journal":{"name":"ISLPED '05. Proceedings of the 2005 International Symposium on Low Power Electronics and Design, 2005.","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2005-08-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131221854","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Dataflow analysis for energy-efficient scratch-pad memory management","authors":"Guangyu Chen, M. Kandemir","doi":"10.1145/1077603.1077682","DOIUrl":"https://doi.org/10.1145/1077603.1077682","url":null,"abstract":"Scratch-pad memories (SPMs) are a serious alternative to conventional cache memories in embedded computing since they allow software to manage data flowing from and into memory components, resulting in a predictable behavior at runtime. The prior studies considered compiler-directed SPM management using both static and dynamic approaches. One of the assumptions under which most of the proposed approaches to data SPM management operate is that the application code is structured with regular loop nests with little or no control flow within the loops. This assumption, while it makes data SPM management relatively easy to implement, limits the applicability of those approaches to the codes involve conditional execution and complex control flows. To address this problem, this paper proposes a novel data SPM management strategy based on dataflow analysis. This analysis operates on a representation that reflects the conditional execution flow of the application and, consequently, it is applicable to a large class of embedded applications, including those with complex control flows.","PeriodicalId":256018,"journal":{"name":"ISLPED '05. Proceedings of the 2005 International Symposium on Low Power Electronics and Design, 2005.","volume":"39 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2005-08-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132402633","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Improving energy efficiency by making DRAM less randomly accessed","authors":"Hai Huang, K. Shin, C. Lefurgy, T. Keller","doi":"10.1145/1077603.1077696","DOIUrl":"https://doi.org/10.1145/1077603.1077696","url":null,"abstract":"Existing techniques manage power for the main memory by passively monitoring the memory traffic, and based on which, predict when to power down and into which low-power state to transition. However, passively monitoring the memory traffic can be far from being effective as idle periods between consecutive memory accesses are often too short for existing power-management techniques to take full advantage of the deeper power-saving state implemented in modem DRAM architectures. In this paper, the authors proposed a new technique that will actively reshape the memory traffic to coalesce short idle periods - which were previously unusable for power management - into longer ones, thus enabling existing techniques to effectively exploit idleness in the memory.","PeriodicalId":256018,"journal":{"name":"ISLPED '05. Proceedings of the 2005 International Symposium on Low Power Electronics and Design, 2005.","volume":"31 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2005-08-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115249193","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"A simple mechanism to adapt leakage-control policies to temperature","authors":"S. Kaxiras, Polychronis Xekalakis, G. Keramidas","doi":"10.1145/1077603.1077617","DOIUrl":"https://doi.org/10.1145/1077603.1077617","url":null,"abstract":"Leakage power reduction in cache memories continues to be a critical area of research because of the promise of a significant pay-off. Various techniques have been developed so far that can be broadly categorized into state-preserving (e.g., drowsy caches) and nonstate preserving (e.g., cache decay). Decay saves more leakage but also incurs dynamic power overhead in the form of induced misses. Previous work has shown that depending on the leakage vs. dynamic power trade-off, one or the other technique can be better. Several factors such as cache architecture, technology parameters and temperature, affect this trade-off. Our work proposes the first mechanism - to the best of our knowledge - that takes into account temperature in adjusting the leakage control policy at run time. At very low temperatures, leakage is relatively weak so the need to tightly control it is not as important as the need to minimize extra dynamic power (e.g., decay-induced misses) or performance loss. We use a hybrid decay+drowsy policy where the main benefit comes from decaying cache lines while the drowsy mode is used to save leakage in long decay intervals. To adapt the decay mode to temperature, we propose a simple triggering mechanism that is based on the principles of decaying 4T thermal sensors and, as such, tied to temperature. The hotter the cache is, the faster cache lines are decayed since it is beneficial to do so with very high leakage currents. Conversely, when the cache temperature is low, our mechanism defers putting cache lines in decay mode to avoid dynamic power overhead but still saves a significant amount of leakage using the drowsy mode. Our study shows that across a wide range of temperatures, the simple adaptability of our proposal yields consistently better results than either the decay mode, or drowsy mode alone, improving over the best by as much as 33%.","PeriodicalId":256018,"journal":{"name":"ISLPED '05. Proceedings of the 2005 International Symposium on Low Power Electronics and Design, 2005.","volume":"36 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2005-08-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115408536","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Runtime identification of microprocessor energy saving opportunities","authors":"W. Bircher, M. Valluri, J. Law, L. John","doi":"10.1145/1077603.1077668","DOIUrl":"https://doi.org/10.1145/1077603.1077668","url":null,"abstract":"High power consumption and low energy efficiency have become significant impediments to future performance improvements in modern microprocessors. This paper contributes to the solution of these problems by presenting: linear regression models for power consumption and a detailed study of energy efficiency in a modern out-of-order superscalar microprocessor. These simple (2-input) yet accurate (2.6% error) models provide a valuable tool for identifying opportunities to apply power saving techniques such as clock throttling and dynamic voltage scaling (DVS). Also, future work in improving energy efficiency is motivated by a detailed analysis of SPEC CPU 2000 workloads. The vast majority of workloads are found to yield very low energy efficiency due to the frequency of level two (L2) cache misses and misspeculated instructions.","PeriodicalId":256018,"journal":{"name":"ISLPED '05. Proceedings of the 2005 International Symposium on Low Power Electronics and Design, 2005.","volume":"310 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2005-08-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115913053","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Replacing global wires with an on-chip network: a power analysis","authors":"Seongmoo Heo, K. Asanović","doi":"10.1145/1077603.1077692","DOIUrl":"https://doi.org/10.1145/1077603.1077692","url":null,"abstract":"This paper explores the power implications of replacing global chip wires with an on-chip network. The authors optimized the network links by varying repeater spacing, link pipelining, and voltage scaling, to significantly reduce the energy to send a bit across chip. An analytic model of large chip designs with an on-chip two-dimensional mesh network was developed and the power savings possible in a 70 nm process for two different design points: a circuit-switched ASIC or FPGA design, and a dynamic packet-switched tiled architecture were estimated. For circuit-switched networks, achievable power savings are 35-50% for a mesh with 1 mm links. The packet switched designs use multiplexing and signal encoding to reduce the number of link wires required, but the router overhead limits peak wire power savings to around 20% with optimal tile sizes of around 2 mm.","PeriodicalId":256018,"journal":{"name":"ISLPED '05. Proceedings of the 2005 International Symposium on Low Power Electronics and Design, 2005.","volume":"99 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2005-08-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128819244","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Modeling and analysis of total leakage currents in nanoscale double gate devices and circuits","authors":"S. Mukhopadhyay, Keunwoo Kim, C. Chuang, K. Roy","doi":"10.1145/1077603.1077608","DOIUrl":"https://doi.org/10.1145/1077603.1077608","url":null,"abstract":"In this paper we model (numerically and analytically) and analyze sub-threshold, gate-to-channel tunneling, and edge direct tunneling leakage in double gate (DG) devices. We compare the leakage of different DG structures, namely, doped body symmetric device with polysilicon gates, intrinsic body symmetric device with metal gates and intrinsic body asymmetric device with different front and back gate material. It is observed that, use of (near-mid-gap) metal gate and intrinsic body devices significantly reduces both the total leakage and its sensitivity to parametric variations in DG circuits.","PeriodicalId":256018,"journal":{"name":"ISLPED '05. Proceedings of the 2005 International Symposium on Low Power Electronics and Design, 2005.","volume":"46 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2005-08-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130815723","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}