Pub Date : 1999-11-07DOI: 10.1109/ICCAD.1999.810709
Y. Kukimoto, R. Brayton
A combinational module is a combinational circuit that can be used under any arrival time condition at the primary inputs. An intellectual property (IP) module, if combinational, is one such example. The false-path-aware delay characterization of a combinational module without disclosing its internal structural detail is crucial for accurate timing analysis of IP-based designs. We address three related issues on delay characterization of combinational modules. We first introduce a new notion called timing-safe replaceability as a way of comparing the timing characteristics of two combinational modules formally. This notion allows us to determine whether a new module is a safe replacement of an original module under any surrounding environment with respect to timing. Second, we consider false path detection of combinational modules. Although false path detection is essential in accurate delay modeling, we argue that the conventional definition of false paths such as floating mode analysis is not appropriate for defining the falsity of a path for a combinational module since the falsity is relative to an arrival time condition. A new definition of false paths, termed strongly false paths, is introduced to resolve this issue. Strongly false paths are those paths that are guaranteed to be false under any arrival time condition, and thus uniquely defined independent of arrival time conditions. Finally, we propose a new algorithm that removes strongly false paths from a combinational module by a circuit transformation. We prove that the resulting circuit is a timing-safe replacement of the original.
{"title":"Timing-safe false path removal for combinational modules","authors":"Y. Kukimoto, R. Brayton","doi":"10.1109/ICCAD.1999.810709","DOIUrl":"https://doi.org/10.1109/ICCAD.1999.810709","url":null,"abstract":"A combinational module is a combinational circuit that can be used under any arrival time condition at the primary inputs. An intellectual property (IP) module, if combinational, is one such example. The false-path-aware delay characterization of a combinational module without disclosing its internal structural detail is crucial for accurate timing analysis of IP-based designs. We address three related issues on delay characterization of combinational modules. We first introduce a new notion called timing-safe replaceability as a way of comparing the timing characteristics of two combinational modules formally. This notion allows us to determine whether a new module is a safe replacement of an original module under any surrounding environment with respect to timing. Second, we consider false path detection of combinational modules. Although false path detection is essential in accurate delay modeling, we argue that the conventional definition of false paths such as floating mode analysis is not appropriate for defining the falsity of a path for a combinational module since the falsity is relative to an arrival time condition. A new definition of false paths, termed strongly false paths, is introduced to resolve this issue. Strongly false paths are those paths that are guaranteed to be false under any arrival time condition, and thus uniquely defined independent of arrival time conditions. Finally, we propose a new algorithm that removes strongly false paths from a combinational module by a circuit transformation. We prove that the resulting circuit is a timing-safe replacement of the original.","PeriodicalId":6414,"journal":{"name":"1999 IEEE/ACM International Conference on Computer-Aided Design. Digest of Technical Papers (Cat. No.99CH37051)","volume":"5 1","pages":"544-549"},"PeriodicalIF":0.0,"publicationDate":"1999-11-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90073019","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}
Pub Date : 1999-11-07DOI: 10.1109/ICCAD.1999.810629
S. Askar, M. Ciesielski
Addresses the problem of the layout design automation of a datapath cell. We present a novel approach to the transistor placement problem for custom datapath design and we demonstrate that it can be applied to practical designs. Our approach is based on an analytical model which employs a mixed integer linear programming (MILP) technique. The novelty and originality of the method is the efficient management of the complexity of the underlying mathematical model. Our prototype tool automatically handles transistor merging, folding and intra-cell component sharing.
{"title":"Analytical approach to custom datapath design","authors":"S. Askar, M. Ciesielski","doi":"10.1109/ICCAD.1999.810629","DOIUrl":"https://doi.org/10.1109/ICCAD.1999.810629","url":null,"abstract":"Addresses the problem of the layout design automation of a datapath cell. We present a novel approach to the transistor placement problem for custom datapath design and we demonstrate that it can be applied to practical designs. Our approach is based on an analytical model which employs a mixed integer linear programming (MILP) technique. The novelty and originality of the method is the efficient management of the complexity of the underlying mathematical model. Our prototype tool automatically handles transistor merging, folding and intra-cell component sharing.","PeriodicalId":6414,"journal":{"name":"1999 IEEE/ACM International Conference on Computer-Aided Design. Digest of Technical Papers (Cat. No.99CH37051)","volume":"26 1","pages":"98-101"},"PeriodicalIF":0.0,"publicationDate":"1999-11-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82552460","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}
Pub Date : 1999-11-07DOI: 10.1109/ICCAD.1999.810623
M. Hershenson, A. Hajimiri, S. S. Mohan, Stephen P. Boyd, T. Lee
Presents a method for optimizing and automating component and transistor sizing for CMOS LC oscillators. We observe that the performance measures can be formulated as posynomial functions of the design variables. As a result, the LC oscillator design problems can be posed as a geometric program, a special type of optimization problem for which very efficient global optimization methods have recently been developed. The synthesis method is therefore fast, and determines the globally optimal design; in particular, the final solution is completely independent of the starting point (which can even be infeasible), and infeasible specifications are unambiguously detected. We can rapidly compute globally optimal trade-off curves between competing objectives such as phase noise and power.
{"title":"Design and optimization of LC oscillators","authors":"M. Hershenson, A. Hajimiri, S. S. Mohan, Stephen P. Boyd, T. Lee","doi":"10.1109/ICCAD.1999.810623","DOIUrl":"https://doi.org/10.1109/ICCAD.1999.810623","url":null,"abstract":"Presents a method for optimizing and automating component and transistor sizing for CMOS LC oscillators. We observe that the performance measures can be formulated as posynomial functions of the design variables. As a result, the LC oscillator design problems can be posed as a geometric program, a special type of optimization problem for which very efficient global optimization methods have recently been developed. The synthesis method is therefore fast, and determines the globally optimal design; in particular, the final solution is completely independent of the starting point (which can even be infeasible), and infeasible specifications are unambiguously detected. We can rapidly compute globally optimal trade-off curves between competing objectives such as phase noise and power.","PeriodicalId":6414,"journal":{"name":"1999 IEEE/ACM International Conference on Computer-Aided Design. Digest of Technical Papers (Cat. No.99CH37051)","volume":"94 1","pages":"65-69"},"PeriodicalIF":0.0,"publicationDate":"1999-11-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80648725","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}
Pub Date : 1999-11-07DOI: 10.1109/ICCAD.1999.810659
M. Jacome, G. Veciana
Traditional lower bound estimates on latency for dataflow graphs assume no data transfer delays. While such approaches can generate tight lower bounds for datapaths with a centralized register file, the results may be uninformative for datapaths with distributed register file structures that are characteristic of VLIW ASIPs (very large instruction word application-specific instruction set processors). In this paper, we propose a latency bound that accounts for such data transfer delays. The novelty of our approach lies in constructing the "window dependency graph" and bounds associated with the problem which capture delay penalties due to operation serialization and/or data moves among distributed register files. Through a set of benchmark examples, we show that the bound is competitive with state-of-the-art approaches. Moreover, our experiments show that the approach can aid an iterative improvement algorithm in determining good functional unit assignments-a key step in code generation for VLIW ASIPs.
{"title":"Lower bound on latency for VLIW ASIP datapaths","authors":"M. Jacome, G. Veciana","doi":"10.1109/ICCAD.1999.810659","DOIUrl":"https://doi.org/10.1109/ICCAD.1999.810659","url":null,"abstract":"Traditional lower bound estimates on latency for dataflow graphs assume no data transfer delays. While such approaches can generate tight lower bounds for datapaths with a centralized register file, the results may be uninformative for datapaths with distributed register file structures that are characteristic of VLIW ASIPs (very large instruction word application-specific instruction set processors). In this paper, we propose a latency bound that accounts for such data transfer delays. The novelty of our approach lies in constructing the \"window dependency graph\" and bounds associated with the problem which capture delay penalties due to operation serialization and/or data moves among distributed register files. Through a set of benchmark examples, we show that the bound is competitive with state-of-the-art approaches. Moreover, our experiments show that the approach can aid an iterative improvement algorithm in determining good functional unit assignments-a key step in code generation for VLIW ASIPs.","PeriodicalId":6414,"journal":{"name":"1999 IEEE/ACM International Conference on Computer-Aided Design. Digest of Technical Papers (Cat. No.99CH37051)","volume":"102 1","pages":"261-268"},"PeriodicalIF":0.0,"publicationDate":"1999-11-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80651557","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}
Pub Date : 1999-11-07DOI: 10.1007/978-1-4615-0292-0_12
L. Carloni, K. McMillan, A. Saldanha, A. Sangiovanni-Vincentelli
{"title":"A methodology for correct-by-construction latency insensitive design","authors":"L. Carloni, K. McMillan, A. Saldanha, A. Sangiovanni-Vincentelli","doi":"10.1007/978-1-4615-0292-0_12","DOIUrl":"https://doi.org/10.1007/978-1-4615-0292-0_12","url":null,"abstract":"","PeriodicalId":6414,"journal":{"name":"1999 IEEE/ACM International Conference on Computer-Aided Design. Digest of Technical Papers (Cat. No.99CH37051)","volume":"126 1","pages":"309-315"},"PeriodicalIF":0.0,"publicationDate":"1999-11-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80334263","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}
Pub Date : 1999-11-07DOI: 10.1109/ICCAD.1999.810684
Inki Hong, M. Potkonjak, L. Guerra
This paper addresses an optimal technique for throughput optimization of general non-linear data flow computations using a set of transformations. Throughput is widely recognized as the most important design metric of the modern DSP and communication applications. Numerous approaches have been proposed for throughput optimization, but most were restricted to limited classes of computations. They have limited effectiveness when applied to large complex non-linear DSP and communication computations. The new technique is used as an optimization engine in a divide-and-conquer global approach for throughput optimization. We demonstrate the effectiveness of the new technique on numerous real-life non-linear designs.
{"title":"Throughput optimization of general non-linear computations","authors":"Inki Hong, M. Potkonjak, L. Guerra","doi":"10.1109/ICCAD.1999.810684","DOIUrl":"https://doi.org/10.1109/ICCAD.1999.810684","url":null,"abstract":"This paper addresses an optimal technique for throughput optimization of general non-linear data flow computations using a set of transformations. Throughput is widely recognized as the most important design metric of the modern DSP and communication applications. Numerous approaches have been proposed for throughput optimization, but most were restricted to limited classes of computations. They have limited effectiveness when applied to large complex non-linear DSP and communication computations. The new technique is used as an optimization engine in a divide-and-conquer global approach for throughput optimization. We demonstrate the effectiveness of the new technique on numerous real-life non-linear designs.","PeriodicalId":6414,"journal":{"name":"1999 IEEE/ACM International Conference on Computer-Aided Design. Digest of Technical Papers (Cat. No.99CH37051)","volume":"100 1","pages":"406-409"},"PeriodicalIF":0.0,"publicationDate":"1999-11-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76504998","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}
Pub Date : 1999-11-07DOI: 10.1109/ICCAD.1999.810669
J. Cortadella, M. Kishinevsky, S. Burns, K. Stevens
This paper describes a method of synthesis of asynchronous circuits with relative timing. Asynchronous communication between gates and modules typically utilizes handshakes to ensure functionality. Relative timing assumptions in the form "event a occurs before event b" can be used to remove redundant handshakes and associated logic. This paper presents a method for automatic generation of relative timing assumptions from the untimed specification. These assumptions can be used for area and delay optimization of the circuit. A set of relative timing constraints sufficient for the correct operation of the circuit is back-annotated to the designer. Experimental results for control circuits of a prototype iA32 instruction length decoding and steering unit called RAPPID (Revolving Asynchronous Pentium(R)Processor Instruction Decoder) shows significant improvements in area and delay over speed-independent circuits.
{"title":"Synthesis of asynchronous control circuits with automatically generated relative timing assumptions","authors":"J. Cortadella, M. Kishinevsky, S. Burns, K. Stevens","doi":"10.1109/ICCAD.1999.810669","DOIUrl":"https://doi.org/10.1109/ICCAD.1999.810669","url":null,"abstract":"This paper describes a method of synthesis of asynchronous circuits with relative timing. Asynchronous communication between gates and modules typically utilizes handshakes to ensure functionality. Relative timing assumptions in the form \"event a occurs before event b\" can be used to remove redundant handshakes and associated logic. This paper presents a method for automatic generation of relative timing assumptions from the untimed specification. These assumptions can be used for area and delay optimization of the circuit. A set of relative timing constraints sufficient for the correct operation of the circuit is back-annotated to the designer. Experimental results for control circuits of a prototype iA32 instruction length decoding and steering unit called RAPPID (Revolving Asynchronous Pentium(R)Processor Instruction Decoder) shows significant improvements in area and delay over speed-independent circuits.","PeriodicalId":6414,"journal":{"name":"1999 IEEE/ACM International Conference on Computer-Aided Design. Digest of Technical Papers (Cat. No.99CH37051)","volume":"65 1","pages":"324-331"},"PeriodicalIF":0.0,"publicationDate":"1999-11-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78578425","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}
Pub Date : 1999-11-07DOI: 10.1109/ICCAD.1999.810634
Tuyen V. Nguyen, P. O'Brien, David W. Winston
This paper presents a general method for computing transient sensitivities using both the direct and adjoint methods in event driven controlled explicit simulation algorithms that employ piecewise linear device models. This transient sensitivity capability is intended to be used in a simulation environment for transistor level analysis and tuning. Results demonstrate the efficiency and accuracy of the proposed techniques. Examples are also presented to illustrate how the transient sensitivity capability is used in timing characterization and circuit tuning.
{"title":"Transient sensitivity computation for transistor level analysis and tuning","authors":"Tuyen V. Nguyen, P. O'Brien, David W. Winston","doi":"10.1109/ICCAD.1999.810634","DOIUrl":"https://doi.org/10.1109/ICCAD.1999.810634","url":null,"abstract":"This paper presents a general method for computing transient sensitivities using both the direct and adjoint methods in event driven controlled explicit simulation algorithms that employ piecewise linear device models. This transient sensitivity capability is intended to be used in a simulation environment for transistor level analysis and tuning. Results demonstrate the efficiency and accuracy of the proposed techniques. Examples are also presented to illustrate how the transient sensitivity capability is used in timing characterization and circuit tuning.","PeriodicalId":6414,"journal":{"name":"1999 IEEE/ACM International Conference on Computer-Aided Design. Digest of Technical Papers (Cat. No.99CH37051)","volume":"240 1","pages":"120-123"},"PeriodicalIF":0.0,"publicationDate":"1999-11-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76917637","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}
Pub Date : 1999-11-07DOI: 10.1109/ICCAD.1999.810675
J. Cong, T. Kong, D. Pan
We study buffer block planning for interconnect-driven floorplanning in deep submicron designs. We first introduce the concept of feasible region (FR) for buffer insertion, and derive closed-form formula for FR. We observe that the FR for a buffer is quite large in general even under fairly tight delay constraints. Therefore, FR gives us a lot of flexibility to plan for buffer locations. We then develop an effective buffer block planning (BBP) algorithm to perform buffer clustering such that the overall chip area and the buffer block number can be minimized. To the best of our knowledge, this is the first in-depth study on buffer planning for interconnect-driven floorplanning with both area and delay consideration.
{"title":"Buffer block planning for interconnect-driven floorplanning","authors":"J. Cong, T. Kong, D. Pan","doi":"10.1109/ICCAD.1999.810675","DOIUrl":"https://doi.org/10.1109/ICCAD.1999.810675","url":null,"abstract":"We study buffer block planning for interconnect-driven floorplanning in deep submicron designs. We first introduce the concept of feasible region (FR) for buffer insertion, and derive closed-form formula for FR. We observe that the FR for a buffer is quite large in general even under fairly tight delay constraints. Therefore, FR gives us a lot of flexibility to plan for buffer locations. We then develop an effective buffer block planning (BBP) algorithm to perform buffer clustering such that the overall chip area and the buffer block number can be minimized. To the best of our knowledge, this is the first in-depth study on buffer planning for interconnect-driven floorplanning with both area and delay consideration.","PeriodicalId":6414,"journal":{"name":"1999 IEEE/ACM International Conference on Computer-Aided Design. Digest of Technical Papers (Cat. No.99CH37051)","volume":"101 1","pages":"358-363"},"PeriodicalIF":0.0,"publicationDate":"1999-11-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79364971","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}
Pub Date : 1999-11-07DOI: 10.1109/ICCAD.1999.810713
A. Kuehlmann, K. McMillan, R. Brayton
This paper describes a probabilistic approach to state space search. The presented method applies a ranking of the design states according to their probability of reaching a given target state based on a random walk model. This ranking can be used to prioritize an explicit or partial symbolic state exploration to find a trajectory from a set of initial states to a set of target states. A symbolic technique for estimating the reachability probability is described which implements a smooth trade-off between accuracy and computing effort. The presented probabilistic state space search complements incomplete verification methods which are specialized in finding errors in large designs.
{"title":"Probabilistic state space search","authors":"A. Kuehlmann, K. McMillan, R. Brayton","doi":"10.1109/ICCAD.1999.810713","DOIUrl":"https://doi.org/10.1109/ICCAD.1999.810713","url":null,"abstract":"This paper describes a probabilistic approach to state space search. The presented method applies a ranking of the design states according to their probability of reaching a given target state based on a random walk model. This ranking can be used to prioritize an explicit or partial symbolic state exploration to find a trajectory from a set of initial states to a set of target states. A symbolic technique for estimating the reachability probability is described which implements a smooth trade-off between accuracy and computing effort. The presented probabilistic state space search complements incomplete verification methods which are specialized in finding errors in large designs.","PeriodicalId":6414,"journal":{"name":"1999 IEEE/ACM International Conference on Computer-Aided Design. Digest of Technical Papers (Cat. No.99CH37051)","volume":"14 1","pages":"574-579"},"PeriodicalIF":0.0,"publicationDate":"1999-11-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75257535","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}