Cortadella, J., Kishinevsky, M., Kondratyev, A., Lavagno, L., Yakovlev, A.: Complete State Encoding Based on Theory of Regions, Proc. ASYNC'  Home/Search   Document Details and Download   Summary   Related Articles   Check

....to several large scale control and data path circuits and microprocessors [14] 22] 15] 23] 35] 39] 20] 2] A number of methods have been developed for the design of asynchronous controllers. Much of the recent work has focused on Petri Net based methods [18] 1] 16] 5] 40] [6], 7] and burst mode methods [27] 9] 25] 43] 17] 31] 13] These two classes of design methods differ in fundamental aspects: the delay model and how the circuit interacts with its environment [10] Petri Net based methods typically synthesize circuits to work correctly regardless of ....

J. Cortadella, M. Kishinevsky, A. Kondratyev, L. Lavagno, and A. Yakovlev, "Complete state encoding based on the theory of regions," in Proceedings of the International Symposium on Advanced Research in Asynchronous Circuits and Systems. New York: IEEE Computer Society Press, 1996.

....to several large scale control and datapath circuits and microprocessors [14] 22] 15] 23] 35] 39] 20] 2] A number of methods have been developed for the design of asynchronous controllers. Much of the recent work has focused on Petri Net based methods [18] 1] 16] 5] 40] [6], 7] and burst mode methods [27] 9] 25] 43] 17] 31] 13] These two classes of design methods di#er in fundamental aspects: the delay model, and how the circuit interacts with its environment [10] Petri Net based methods typically synthesize circuits to work correctly regardless of ....

J. Cortadella, M. Kishinevsky, A. Kondratyev, L. Lavagno, and A. Yakovlev. Complete state encoding based on the theory of regions. In Proc. International Symposium on Advanced Research in Asynchronous Circuits and Systems. IEEE Computer Society Press, March 1996.

....must meet somewhat stricter timing constraints (fundamental mode assumption [64] which in practice are often easily met) but allow greater flexibility in the synthesis path. A number of tools have been developed for both burst mode [57] 65] 66] 67] 59] 68] and STG [69] 60] 70] [71], 72] 73] synthesis; these have been applied to a number of real world designs [74] 13] 8] 75] 73] 76] An alternative approach has also been proposed, called timed circuits [77] which incorporates user specified timing information to optimize the circuits. Compiling asynchronous ....

J. Cortadella, M. Kishinevsky, A. Kondratyev, L. Lavagno, and A. Yakovlev, "Complete state encoding based on the theory of regions," in Proceedings of the International Symposium on Advanced Research in Asynchronous Circuits and Systems (Async96). November 1996, pp. 36--47, IEEE Computer Society Press.

....events that have appeared as the result of the composition (projects the transition system onto the external events) 3. re synthesizes a new simplified Petri net from the transition system obtained after the projection. Moreover, a new algorithm for state encoding has been integrated in petrify [4] that allows to directly obtain an implementable STG. We refer the reader to [5] for further details on the synthesis of Petri nets from transition systems. 3 Modeling processes with Petri nets In this section we provide some terminology and definitions related to formalisms we will use later. ....

J. Cortadella, M. Kishinevsky, A. Kondratyev, L. Lavagno, and A. Yakovlev. Complete state encoding based on theory of regions. In Proc. International Symposium on Advanced Research in Asynchronous Circuits and Systems, Aizu, Japan, March 1996.

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Cortadella, J., Kishinevsky, M., Kondratyev, A., Lavagno, L., Yakovlev, A.: Complete State Encoding Based on Theory of Regions, Proc. ASYNC'

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Cortadella, J., Kishinevsky, M., Kondratyev, A., Lavagno, L., Yakovlev, A.: Complete State Encoding Based on Theory of Regions, Proc. ASYNC'

....similar to classical logic design of nite state machines. It can be seen as a set of equivalent transformations of the original speci cation (e.g. by means of event insertion) to satisfy the implementability properties. It includes state assignment by solving the Complete State Coding problem [4, 5] coupled with logic minimization and speedindependent technology mapping to a target library [51, 3, 25] Related approaches can be also found in [56, 1, 30] Methods based on the theory of state regions [12, 40, 6] provide an ecient framework for the solution of the above tasks, as they allow us ....

....the CSC property, then it can be implemented by a circuit with n (arbitrarily complex) logic gates. CSC con icts can be resolved by encoding the corresponding states with additional signals. These signals distinguish the CSC con icts by assigning the corresponding states di erent binary codes. In [5] an e ective procedure for inserting additional signals to resolve CSC con icts is presented. This procedure preserves the trace equivalence and speed independence of the original speci cation and always converges for safe STGs. Persistency All the properties considered up to now do not ....

[Article contains additional citation context not shown here]

J. Cortadella, M. Kishinevsky, A. Kondratyev, L. Lavagno, and A. Yakovlev. Complete state encoding based on the theory of regions. In International Symposium on Advanced Research in Asynchronous Circuits and Systems, Aizu, Japan, March 1996.

....7. Similarly merge every transition on internal signals of the rst STG and the corresponding dummy of the second STG into a single transition labelled as the corresponding internal transition. This algorithm assumes that the original STG has a complete state coding (CSC) property as de ned in [6]. This means that the appropriate tool, such as Petrify, should be run to check this property and, if needed, to insert CSC internal signals before the application of the above algorithm. The original speci cation conforming CSC guarantees that the algorithm produces the STG having the property of ....

J. Cortadella, M. Kishinevsky, A. Kondratyev, L. Lavagno, and A. Yakovlev. Complete state encoding based on the theory of regions. In Proc. International Symposium on Advanced Research in Asynchronous Circuits and Systems. IEEE Computer Society Press, Mar. 1996.

....lies. Apart from interaction with the designer, which is a major motivation for this work, we also address the issue of extracting explicit causal relations in order to be able to apply analysis and synthesis techniques which rely on explicit causality and concurrency information ( 45] 29] In [14], 15] we showed that regions, sets of states corresponding to places in PNs, are tightly connected with properties that must be preserved across the state encoding process for asynchronous circuits. Hence, regions and their intersections can be efficiently used for state signal insertion and, ....

# J. Cortadella, M. Kishinevsky, A. Kondratyev, L. Lavagno, and A. Yakovlev, "Complete State Encoding Based on the Theory of Regions, " Proc. Int'l Symp. Advanced Research in Asynchronous Circuits and Systems, pp. 36-47, Mar. 1996.

.... 7] The approach combines together efficient algebraic factorization techniques used in multi level combinational logic synthesis (finding candidates for decomposition) and speed independence preserving signal insertion (the latter idea originated in [17] and was implemented efficiently in [6]) The main contribution of this paper is a generalisation and extension of the above basic idea so as to cover both combinational and sequential decomposition. We have 1 developed a body of theory that allows us to prune the search space when looking for solutions. We continue to use ....

....iff: 1) for each event a in A, if a is persistent in A, then it remains persistent in A 0 , and (2) A 0 is deterministic and commutative. The formal conditions for the set of states r to be a SIP set can be given in terms of intersections of r with the so called state diamonds of SG [6]. These conditions are illustrated by Figure 4, where all possible cases of the illegal intersections of r with state diamonds are shown. It was shown in [6] that the insertion of a signal by means of a SIP set is a necessary and sufficient condition to preserve the speed independence of a ....

[Article contains additional citation context not shown here]

J. Cortadella, M. Kishinevsky, A. Kondratyev, L. Lavagno, and A. Yakovlev. Complete state encoding based on the theory of regions. In International Symposium on Advanced Research in Asynchronous Circuits and Systems, Aizu, Japan, March 1996.

....technology mapping to a target library. The final net list is guaranteed to be speed independent, i.e. hazard free under any distribution of gate delays and multiple input changes satisfying the initial specification. The tool has been used for synthesis of PNs and PNs composition [10] synthesis [7, 8, 9] and re synthesis [29] of asynchronouscontrollers and can be also applied in areas related with the analysis of concurrent programs. This paper provides an overview of petrify and the theory behind its main functions. 1 Introduction Petri nets [26, 30] are a widespread formalism to model ....

....a designer to play with a PN like specification, performing equivalent transformations of PNs, and or transformations of other specifications into PNs under different design constraints and optimization criteria. Figure 1 shows our framework for synthesizing PNs and transforming specifications. In [7, 8, 9] we show that regions are tightly connected with the set of properties that must be preserved across the state encoding and technology mapping process for asynchronous circuits. Hence, regions and their intersections can be efficiently used for state signal insertion. Therefore, sets of states ....

[Article contains additional citation context not shown here]

J. Cortadella, M. Kishinevsky,A. Kondratyev,L. Lavagno, and A. Yakovlev. Complete state encoding based on the theory of regions. In International Symposium on Advanced Research in Asynchronous Circuits and Systems, pages 36--47, March 1996.

....similar to classical logic design of finite state machines. It can be seen as a set of equivalent transformations of the original specification (e.g. by means of event insertion) to satisfy the implementability properties. It includes state assignment by solving the Complete State Coding problem [4, 5] coupled with logic minimization and speedindependent technology mapping to a target library [51, 3, 25] Related approaches can be also found in [56, 1, 30] Methods based on the theory of state regions [12, 40, 6] provide an efficient framework for the solution of the above tasks, as they allow ....

....CSC property, then it can be implemented by a circuit with n (arbitrarily complex) logic gates. CSC conflicts can be resolved by encoding the corresponding states with additional signals. These signals distinguish the CSC conflicts by assigning the corresponding states different binary codes. In [5] an effective procedure for inserting additional signals to resolve CSC conflicts is presented. This procedure preserves the trace equivalence and speed independence of the original specification and always converges for safe STGs. Persistency All the properties considered up to now do not ....

[Article contains additional citation context not shown here]

J. Cortadella, M. Kishinevsky, A. Kondratyev, L. Lavagno, and A. Yakovlev. Complete state encoding based on the theory of regions. In International Symposium on Advanced Research in Asynchronous Circuits and Systems, Aizu, Japan, March 1996.

....lies. Apart from interaction with the designer, which is a major motivation for this work, we also address the issue of extracting explicit causal relations in order to be able to apply analysis and synthesis techniques which rely on explicit causality and concurrency information ( 45] 29] In [14, 15] we show that regions, sets of states corresponding to places in PNs, are tightly connected with properties that must be preserved across the state encoding process for asynchronous circuits. Hence, regions and their intersections can be efficiently used for state signal insertion and, therefore, ....

J. Cortadella, M. Kishinevsky, A. Kondratyev, L. Lavagno, and A. Yakovlev. Complete state encoding based on the theory of regions. In International Symposium on Advanced Research in Asynchronous Circuits and Systems, pages 36--47, March 1996.

....mapping to a target library. The final net list is guaranteed to be speed independent, i.e. hazard free under any distribution of gate delays and multiple input changes satisfying the initial specification. The tool has been used for synthesis of PNs and PNs composition [10] synthesis [7, 9, 8] and re synthesis [29] of asynchronous controllers and can be also applied in areas related with the analysis of concurrent programs. This paper provides an overview of petrify and the theory behind its main functions. 1 Introduction Petri nets [30, 26] are a widespread formalism to model ....

....a designer to play with a PN like specification, performing equivalent transformations of PNs, and or transformations of other specifications into PNs under different design constraints and optimization criteria. Figure 1 shows our framework for synthesizing PNs and transforming specifications. In [7, 9, 8] we show that regions are tightly connected with the set of properties that must be preserved across the state encoding and technology mapping process for asynchronous circuits. Hence, regions and their intersections can be efficiently used for state signal insertion. Therefore, sets of states ....

[Article contains additional citation context not shown here]

J. Cortadella, M. Kishinevsky, A. Kondratyev, L. Lavagno, and A. Yakovlev. Complete state encoding based on the theory of regions. In International Symposium on Advanced Research in Asynchronous Circuits and Systems, pages 36--47, March 1996.

....a designer to play with a PN like specification, performing equivalent transformations of PNs, and or transformations of other specifications into PNs under different design constraints and optimization criteria. Fig. 1 shows our framework for synthesizing PNs and transforming specifications. In [8, 10, 9] we show that regions are tightly connected with the set of properties that must be preserved across the state encoding and technology mapping process for asynchronous circuits. Hence, regions and their intersections can be efficiently used for state signal insertion. Therefore, sets of states ....

....commutativity and output event persistency guarantee speed independence of its circuit implementation. Insertion sets should be chosen in such a way that persistency and commutativity of the original events are not violated. The following property of insertion sets, based on theory developed in [8], provides a rationale for our approach. Property 4.1 Regions, excitation regions and intersections of pre regions can be used as insertion sets in a commutative and deterministic TS. This property suggests that the good candidates for insertion sets should be sought on the basis of regions and ....

J. Cortadella, M. Kishinevsky, A. Kondratyev, L. Lavagno, and A. Yakovlev. Complete state encoding based on the theory of regions. In International Symposium on Advanced Research in Asynchronous Circuits and Systems, pages 36--47, March 1996.

....(SIP set) iff: 1) for each event a in A, if a is persistent in A, then it remains persistent in A 0 , and (2) A 0 is deterministic and commutative. The formal conditions for the set of states r to be a SIP set can be given in terms of intersections of r with the so called state diamonds of SG [5]. These conditions are illustrated by Figure 4, where all possible cases of illegal intersections of r with state diamonds are shown. The first (rather ER(x) a) d c b a (b) ER(x) d x c b x c x b x x a Figure 3: Event insertion scheme: a) before insertion, b) after insertion inefficient) ....

.... b a (b) ER(x) d x c b x c x b x x a Figure 3: Event insertion scheme: a) before insertion, b) after insertion inefficient) method for finding SIP sets based on a reduction to the satisfiability problem was proposed in [16] An efficient method based on the theory of regions has been described in [5]. d s1 r a s2 d a s4 s3 d s4 s3 d s1 a s2 r s3 d s1 a r s2 d s4 a) b) c) Figure 4: Possible violations of SIP conditions Assume that the set of states S in an SG is partitioned into two subsets which are to be encoded by means of an additional signal. This new signal can be added either in order ....

J. Cortadella, M. Kishinevsky, A. Kondratyev, L. Lavagno, and A. Yakovlev. Complete state encoding based on the theory of regions. In International Symposium on Advanced Research in Asynchronous Circuits and Systems, Aizu, Japan, March 1996.

....mapping problem for speed independent circuits. We do not rely on unbounded fanin libraries, nor on user hints on how to decompose a given non implementable gate. Furthermore, we can formulate the implementation problem in the same framework as state encoding for asynchronous circuits ([6]) Hence we can perform logic minimization and technology mapping while doing state encoding . This allows us to obtain better results than previous techniques that separated the state encoding, technology independent implementation and (with the limitation seen above) technology mapping steps. ....

J. Cortadella, M. Kishinevsky, A. Kondratyev, L. Lavagno, and A. Yakovlev. Complete state encoding based on the theory of regions. In International Symposium on Advanced Research in Asynchronous Circuits and Systems, Aizu, Japan, March 1996.

....iff: 1) for each event a in A, if a is persistent in A, then it remains persistent in A 0 , and (2) A 0 is deterministic and commutative. The formal conditions for the set of states r to be a SIP set can be given in terms of intersections of r with the so called state diamonds of SG [5]. A new signal is inserted using an I partition of a set of states S into four blocks: fER(x ) QR(x ) ER(x Gamma) QR(x Gamma)g (similar to [15] QR(x Gamma) QR(x ) defines the states in which x will have the stable value 0 (1) ER(x ) ER(x Gamma) defines the excitation region of x in the ....

J. Cortadella, M. Kishinevsky, A. Kondratyev, L. Lavagno, and A. Yakovlev.Complete state encoding based on the theory of regions. In InternationalSymposiumon AdvancedResearch in Asynchronous Circuits and Systems, Aizu, Japan, March 1996.

....lies. Apart from interaction with the designer, which is a major motivation for this work, we also address the issue of extracting explicit causal relations in order to be able to apply analysis and synthesis techniques which rely on explicit causality and concurrency information ( 36] 22] In [10, 12] we show that regions sets of states corresponding to places in PNs, are tightly connected with the set of properties that must be preserved across the state encoding process for asynchronous circuits. Hence, regions and their intersections can be efficiently used for state signal insertion. ....

J. Cortadella, M. Kishinevsky, A. Kondratyev, L. Lavagno, and A. Yakovlev. Complete state encoding based on the theory of regions. In Proc. of the 2nd. Int. Symp. on Advanced Research in Asynchronous Circuits and Systems, pages 36--47, March 1996.

No context found.

J. Cortadella, M. Kishinevsky, A. Kondratyev, L. Lavagno, and A. Yakovlev. Complete state encoding based on theory of regions. In Proc. International Symposium on Advanced Research in Asynchronous Circuits and Systems, Aizu, Japan, March 1996.

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