Synopsys, Inc.

O-in Design Automation, Inc.

Other

Mentor Graphics Corporation

Jing Chyuarn Lin

Chian-Min Richard Ho

Ping Fai Yeung

Kalyana C Mulam

Tai An Ly

Lawrence Curtis Widdoes, Jr

Jean-Charles Giomi

Paul Andrew Wilcox

Robert Kristianto Mardjuki

David Lansing Dill

Paul Il Estrada

Paul Ii Estrada

Brent L Gregory

Changge Qiao

Emil F Girczyc

Paul Estrada, Ii

Andrew Seawright

Srinivas Raghvendra

Trinanjan Chatterjee

Mahesh A Iyer

Kayhan Kucukcakar

Pei-Hsin Ho

Anand Arunachalam

Prashant Saxena

Vishal Khandelwal

Jinan Lou

Suman Chatterjee

Chi-Min Chu

Technology is disclosed for placement of single-bit flip-flops and multi-bit flip-flops. Single-bit flip-flops with replaced with multi-bit flip-flops and/or relative placement groups of single-bit flip-flops.

Placement of single-bit and multi-bit flip-flops

A method of improving pre-route and post-route correlation can include performing an initial placement, virtual routing, and lower-effort actual routing for the design. The results of the virtual routing and lower-effort actual routing can be compared to identify nets having miscorrelation. Based on the nets having at least a predetermined miscorrelation, one or more patterns can be defined. At this point, net routing constraints and/or scaling factors can be assigned to nets matching the defined patterns. These net routing constraints and scaling factors can be applied to the nets of the design that match the patterns. Optimized placement and a higher-effort actual routing of the design can be performed using the nets with the applied net routing constraints and scaling factors. An optimized, routed design can be generated as output.

Pre-route and post-route net correlation with defined patterns

A persistence-driven optimization technique is provided in which nets can be ranked based on unpredictability and likely quality of result impact. The top nets in that ranking can be routed and their parasitics extracted. A timing graph can be back-annotated with route-based delays and parasitics for the selected nets. At this point, synthesis can be run using actual route-based delays and parasitics for the selected nets, with their routes being updated incrementally as needed. In one embodiment, the nets can be re-ranked after synthesis. Finally, these routes can be preserved across the subsequent global routing of the remaining nets.

Interconnect-driven physical synthesis using persistent virtual routing

A method for reaching signoff closure in an ECO (engineering change order) process involves the use of violation context data from the signoff tool as the basis for design layout modifications in an implementation tool. The violation context data includes violation information other than violation location/path information. Because the signoff tool, and more specifically, the signoff algorithm used by that tool is the most accurate model of actual IC behavior, the use of violation context data generated by the signoff tool to implement changes to the design layout will generally produce appropriate and effective results. By accessing this violation context data from the signoff tool, an implementation tool need not rely on its less accurate implementation analysis to determine the optimal design layout modifications for correcting violations detected by the signoff tool.

Engineering change order process optimization

A programmed computer searches for functional defects in a description of a circuit undergoing functional verification in the following manner. The programmed computer simulates the functional behavior of the circuit in response to a test vector, automatically restores the state of the simulation without causing the simulation to pass through a reset state, and then simulates the functional behavior of the circuit in response to another test vector. A predetermined rule can be used to identify test vectors to be simulated, and the predetermined rule can depend upon a measure of functional verification, including the number of times during simulation when a first state transition is performed by a first-controller at the same time as a second state transition is performed by a second controller. During simulation of the test vectors, manually generated tests or automatically generated checkers can monitor portions of the circuit for defective behavior.

Method for automatically searching for functional defects in a description of a circuit

A programmed computer generates descriptions of circuits (called 'checkers') that flag functional defects in a description of a circuit undergoing functional verification. The programmed computer automatically converts the circuit's description into a graph, automatically examines the graph for instances of a predetermined arrangement of nodes and connections, and automatically generates instructions that flag a behavior of a device represented by the instance in conformance with a known defective behavior. The checkers can be used during simulation or emulation of the circuit, or during operation of the circuit in a semiconductor die. The circuit's description can be in Verilog or VHDL and the automatically generated checkers can also be described in Verilog or VHDL. Therefore, the checkers can co-simulate with the circuit, monitoring the simulated operation of the circuit and flagging defective behavior. The programmed computer can automatically determine load conditions of registers in the circuit and automatically generate checkers to flag data loss in the registers. Some of the checkers may use signals generated by other checkers.

Method for automatically generating checkers for finding functional defects in a description of circuit

A programmed computer searches for functional defects in a description of a circuit undergoing functional verification in the following manner. The programmed computer simulates the functional behavior of the circuit in response to a test vector, automatically restores the state of the simulation without causing the simulation to pass through a reset state, and then simulates the functional behavior of the circuit in response to another test vector. A predetermined rule can be used to identify test vectors to be simulated, and the predetermined rule can depend upon a measure of functional verification, including the number of times during simulation when a first state transition is performed by a first controller at the same time as a second state transition is performed by a second controller. During simulation of the test vectors, manually generated tests or automatically generated checkers can monitor portions of the circuit for defective behavior.

A programmed computer generates descriptions of circuits (called &ldquo;checkers&rdquo;) that flag functional defects in a description of a circuit undergoing functional verification. The programmed computer automatically converts the circuit's description into a graph, automatically examines the graph for instances of a predetermined arrangement of nodes and connections, and automatically generates instructions that flag a behavior of a device represented by the instance in conformance with a known defective behavior. The checkers can be used during simulation or emulation of the circuit, or during operation of the circuit in a semiconductor die The circuit's description can be in Verilog or VHDL and the automatically generated checkers can also be described in Verilog or VHDL. Therefore, the checkers can co-simulate with the circuit, monitoring the simulated operation of the circuit and flagging detective behavior. The programmed computer can automatically determine load conditions of registers in the circuit and automatically generate checkers to flag data loss in the registers. Some of the checkers may use signals generated by other checkers.

Method for automatically generating checkers for finding functional defects in a description of a circuit

A programmed computer generates descriptions of circuits (called &ldquo;checkers&rdquo;) that flag functional defects in a description of a circuit undergoing functional verification. The programmed computer automatically converts the circuit's description into a graph, automatically examines the graph for instances of a predetermined arrangement of nodes and connections, and automatically generates instructions that flag a behavior of a device represented by the instance in conformance with a known defective behavior. The checkers can be used during simulation or emulation of the circuit, or during operation of the circuit in a semiconductor die. The circuit's description can be in Verilog or VHDL and the automatically generated checkers can also be described in Verilog or VHDL. Therefore, the checkers can co-simulate with the circuit, monitoring the simulated operation of the circuit and flagging defective behavior. The programmed computer can automatically determine load conditions of registers in the circuit and automatically generate checkers to flag data loss in the registers. Some of the checkers may use signals generated by other checkers.

This invention provides a method for displaying circuit analysis results corresponding to parts of the circuit near the portion of the hardware description language (HDL) specification that generated that part of the circuit. The invention also includes a method for using probe statements in the HDL specification to mark additional points in the initial circuit that should not be eliminated during optimization. This improves the ability to display circuit analysis results near the appropriate part of the HDL specification.

Architecture and methods for a hardware description language source

A digital circuit is synthesized from a text description of a digital system. During synthesis, a parse tree with parse nodes is constructed and retained. The relationship between the parse nodes and the circuit elements synthesized from those parse nodes is retained. Using that relationship, analysis results associated with circuit elements can be related to the text that generated those circuit elements. In particular, the analysis results can be used to set the display characteristics, such as font or size, of the text associated with those results.

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Sunnyvale, CA, United States of America

Jing Chyuarn Lin