Monterey Design Systems, Inc.

Synopsys, Inc.

Abhijeet Chakraborty

Lawrence Thomas Pileggi

Douglas B Boyle

Sharad Malik

Gary K Yeap

Majid Sarrafzadeh

Salil Ravindra Raje

Feroze P Taraporevala

Lilly Shieh

Dennis Yamamoto

David John Seibert

Eric McCaughrin

Emre Tuncer

James S Koford

Christopher J Dunn

David Gluss

Mohammad Ziaullah Khan

Van E Morgan

Tong Gao

Robert E Shortt

Dinesh D Gaitonde

Satyamurthy Pullela

Joseph T Rahmeh

Altan Odabasioglu

Pingkan Fok

Sam Jung Kim

Archie Li

Yau-Tsun Steven Li

Ramoji Karumuri Rao

Satamurthy Pullela

Maurizio Damiani

Tsuwei Ku

A system expands an existing library based on simultaneous optimization of a circuit design being built and the library cells being used. The system receives a library of cells and a circuit design and performs synthesis and optimization of the circuit design. The system evaluates the circuit design to identify portions that may be candidates for new library cells. The system analyzes the library to determine whether there is an existing library cell that can be used, whether the new libcell should be added to the library, or whether the new libcell should replace an existing libcell. The system performs modeling for the new libcell to measure the improvement obtained by use of the new libcell. The system recommends the new libcell for addition to the library based on the performance modeling.

Library design and co-optimization with a circuit design

Systems and techniques are described for optimizing an integrated circuit (IC) design. Before routing is performed on the IC design in an IC design flow, an IC design tool can iteratively perform a set of operations, the set of operations comprising: (1) modifying a net in the IC design to obtain a modified net, (2) determining a metal layer for routing the modified net, (3) computing a resistance value and a capacitance value of the modified net based on the metal layer, and (4) computing a delay value for the modified net based on the resistance value and the capacitance value.

Integrated metal layer aware optimization of integrated circuit designs

The present invention, generally speaking, provides a placement method for the physical design of integrated circuits in which natural topological feature clusters (topo-clusters) are discovered and exploited during the placement process. Topo-clusters may be formed based on various criteria including, for example, functional similarity, proximity (in terms of number of nets), and genus. Genus refers to a representation of a netlist in terms of a number of planar netlists&#x2014;netlists in which no crossing of nets occurs. Topo-clusters drive initial placement, with all of the gates of a topo-cluster being placed initially in a single bin of the placement layout or within a group of positionally-related bins. The portion of a topo-cluster placed within a given bin is called a quanto-cluster. An iterative placement refinement process then follows, using a technique referred to herein as Geometrically-Bounded FM (GBFM), and in particular Dual GBFM. In GBFM, FM is applied on a local basis to windows encompassing some number of bins. From iteration to iteration, windows may shift position and vary in size. When a region bounded by a window meets a specified cost threshold in terms of a specified cost function, that region does not participate. The cost function takes account of actual physical metrics&#x2014;delay, area, congestion, power, etc. 'Dual' refers to the fact that each iteration has two phases. During a first phase, FM is performed within a region on a quanto-cluster basis. During a second phase, FM is performed within the region on a gate basis. GBFM occurs in the context of recursive quadrisection. Hence, after GBFM has been completed, a further quadrisection step is performed in which each bin is divided into four bins, with a quarter of the gates of the original bin being placed in the center of each of the resulting bins. GBFM then follows, and the cycle repeats until each bin contains a fairly small number of gates. Following the foregoing global placement process, the circuit is then ready for detailed placement in which cells are assigned to placement rows.

Placement method for integrated circuit design using topo-clustering

A timing graph representing timing information of an integrated circuit design may change after modifications are made to the integrated circuit design. The modifications change timing parameters for edges in the timing graph. The measure of these changes may be computed at a computed measure compared to a threshold. In the event the measure exceeds the threshold, the edges in the timing graph that need to change in response to the modifications are updated. Otherwise, the current edges in the timing graph are continued to be used. The threshold is set in accordance with the accuracy and efficiency requirements of an electronic design automation tool.

Method for accurate and efficient updates of timing information logic synthesis, placement and routing for integrated circuit design

The disclosure describes a placement method for the physical design of integrated circuits in which natural topological feature clusters are discovered and exploited during the placement process is disclosed. Topo-clusters drive initial placement, with all of the gates of a topo-cluster being placed initially in a single bin of the placement layout or within a group of positionally-related bins. An iterative placement refinement process is done using a technique referred to as Dual Geometrically-Bounded FM (GBFM). GBFM is applied on a local basis to windows encompassing a number of bins. From iteration to iteration, windows may shift position and vary in size. When a region bounded by a window meets a specified cost threshold in terms of a specified cost function, that region stops participating. Following the foregoing global placement process the circuit is then ready for detailed placement in which cells are assigned to placement rows.

A design tool for integrated circuits includes a placement tool which concurrently places logic gates and interconnect. In one embodiment, the logic gates are placed into bins and virtual buffers are inserted between logic gates mapped to different bins. Placement and interconnect wire lengths and densities are successively improved leading to removal of some buffers and actualization of the virtual buffers.

System and method for concurrent buffer insertion and placement of logic gates

A method for design optimization using logical and physical information is provided. In one embodiment, a method for design optimization using logical and physical information, includes receiving a behavioral description of an integrated circuit or a portion of an integrated circuit, optimizing placement of circuit elements in accordance with a first cost function, and optimizing logic of the circuit elements in accordance with a second cost function, in which the optimizing placement of the circuit elements and the optimizing logic of the circuit elements are performed concurrently. The method can further include optimizing routing in accordance with a third cost function, in which the optimizing routing, the optimizing placement of the circuit elements, and the optimizing logic of the circuit elements are performed concurrently.

Method for design optimization using logical and physical information

This invention recognizes the ability of logic optimization to help placement relieve congestion. Different types of logic optimizations are used to help placement relieve congestion. In one type of optimization, the speed of parts of the circuit is improved by selecting faster cells. In another type of optimization, the topology of the circuit is changed such that placement can now move cells, which could not have been moved before, to reduce congestion and thus enable routing. A distinguishing feature of this methodology is that it not only uses the placement information for interconnection delay/area estimates during logic optimization, but also uses logic optimization to aid the physical placement steps by providing support to placement so that the congestion of the circuit is improved. The aim is to avoid getting into a situation where the placed circuit cannot be routed.

Method for logic optimization for improving timing and congestion during placement in integrated circuit design

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Sunnyvale, CA, United States of America

Abhijeet Chakraborty