Abstract: Methods and apparatus for a physical “sign-off” prototype tool that includes a prototype tool that generates a physical prototype for a design and a optimization tool that provides a designer with the option to further optimize the physical prototype before signing off on the design. In either situation, the “sign-off” prototype provides a forward prediction of the area, timing and performance of the final GDS of the design generated by a physical implementation tool.

Abstract: Progressively optimized clock tree/mesh construction is performed concurrently with placement of all remaining objects. Clock tree/mesh is specified loosely for initial placement, then followed by progressive detailed placement. In particular, preferred approach provides automated and reliable solution to clock tree/mesh construction, occuring concurrently with placement process so that clock tree wiring and buffering considers and influences placement and wiring of all other objects, such as logic gates, memory elements, macrocells, etc. Hence, in this concurrent manner, clock tree/mesh pre-wiring and pre-buffering may be based on construction of approximate clock tree using partitioning information only, i.e., prior to object placement. Further, present approach provides modified DME-based clock tree topology construction without meandering, and recursive algorithm for buffered clock tree construction.

Abstract: An automated method of designing large digital integrated circuits using a software program to partition the design into physically realizable blocks and then create the connections between blocks so as to maximize operating speed and routability while minimizing the area of the resulting integrated circuit. Timing and physical constraints are generated for each physically realizable block so that standard-cell place and route software can create each block independently as if it were a separate integrated circuit.

Abstract: 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.

Abstract: Method to optimize net lists used in the design and fabrication of integrated circuits by using simultaneous placement optimization, logic function optimization and net buffering algorithms. Method simultaneously obtains a placement of logic functions, mapping of logic functions on to library elements and buffering of nets connecting the logic functions.

Abstract: An electronic computer aided design system provides for automated operation of a plurality of design tools to produce multiply design solutions to an initial circuit layout. Through the user entry of relative weights for: power, timing and area, different solutions to an initial layout can be generated exhibiting the requested balance of improvements over the original layout. A novel parts placement process is disclosed which prioritizes the reconfiguration of the initial design in a manner which assures that the multiple solutions will be generated which exhibit improved performance over the original layout in accordance with the priorities established by the user.

Abstract: 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.

Abstract: A system is disclosed for compacting an initial electronic layout of cells within an initial layout boundary. The system includes forming paths extending from a bottom edge of the layout to a top edge. The paths intersect cells of the initial layout. The system determines which of the paths are critical paths. Critical cuts are then determined. A critical cut is a cut that severs critical paths. A set of cells associated with a critical cut are removed from the layout and replaced in order to reduce the initial layout boundary.

Abstract: 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.

Abstract: A design tool for integrated circuits includes a placement tool which places logic gates and interconnect components concurrently. Probabilistic interconnect models are used to represent the collection of possible interconnect routings that provide acceptable circuit performance and routing area.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: A method for optimizing layout design using logical and physical information performs placement, logic optimization and routing and routing estimates concurrently. In one embodiment, circuit elements of the integrated circuit is partitioned into clusters. The clusters are then placed and routed by iterating over an inner-loop and an outer-loop according to cost functions in the placement model which takes into consideration interconnect wiring delays. Iterating over the inner-loop, logic optimization steps improves the cost functions of the layout design. Iterating over the outer-loop, the size of the clusters, hence the granularity of the placement, is refined until the level of individual cells is reached. The present method is especially suited for parallel processing by multiple central processing units accessing a shared memory containing the design data base.