Abstract: An automatic custom block composition tool for composing custom blocks of an integrated circuit (IC) design that may include non-standard library cells. The tool includes program instructions that are executable to create and use a placement control file that includes instructions for use by the custom block composition tool to place the one or more non-standard library cells into the custom block layout. In addition, the program instructions may instantiate a leafcell for each non-standard and each standard library cell included in a netlist. The program instructions may access the placement control file and place each leafcell in a row of the custom block layout according to the placement control file. The program instructions may also pre-route power, clock and critical network signals, and generate a router control file used during remaining routing of the custom block by a conventional router tool.

Abstract: An automatic custom block composition tool for composing custom blocks of an integrated circuit (IC) design that may include non-standard library cells. The tool includes program instructions that are executable to create and use a placement control file that includes instructions for use by the custom block composition tool to place the one or more non-standard library cells into the custom block layout. In addition, the program instructions may instantiate a leafcell for each non-standard and each standard library cell included in a netlist. The program instructions may access the placement control file and place each leafcell in a row of the custom block layout according to the placement control file. The program instructions may also pre-route power, clock and critical network signals, and generate a router control file used during remaining routing of the custom block by a conventional router tool.

Abstract: A technique for improving multiple critical timing paths that exhibit similar characteristics has been discovered. The technique efficiently improves multiple critical timing paths by reducing the number of unique critical timing path patterns for analysis. In some embodiments of the present invention a method for use in connection with an integrated circuit design includes identifying distinct timing paths of the integrated circuit design. The distinct timing paths have timing violations. The method includes associating a first plurality of the distinct timing paths with a first set of timing paths. Individual ones of the first plurality belonging to a second set of timing paths and include a first common characteristic. The method includes improving the first set of timing paths based at least in part on an improvement to an individual timing path of the first set of timing paths.

Abstract: One embodiment of the present invention provides a circuit which blocks a keeper from interfering with a dynamic node during an evaluation phase for a dynamic wide-NOR structure. The circuit contains a precharge device which is coupled to the dynamic node. The precharge device precharges the dynamic node during a precharge phase. The circuit also contains a plurality of parallel pull-down transistors which are coupled to the dynamic node. The pull-down transistors conditionally discharge the dynamic node during the evaluate phase. The keeper sustains a precharged value on the dynamic node, thereby preventing a false evaluation caused by a leakage current through the parallel pull-down transistors. In addition, the circuit contains a feedback gating device which is coupled between the keeper and the dynamic node. During the evaluation phase, the feedback gating device blocks the keeper, so that the parallel pull-down transistors can discharge the dynamic node without interference from the keeper.

Abstract: The capacitances of one or more inputs/outputs of a circuit are estimated by using an extraction tool (120) to extract information associated with the inputs/outputs from a netlist. The information includes information associated with circuit devices directly connected to the inputs/outputs, particularly information related to device connectivity and the feature sizes of the device. Once the information is extracted, a capacitance determination element (130) aggregates the feature sizes of all the circuit devices connected to each respective input or output, to obtain aggregate feature sizes for each respective input/output. The aggregate feature size is used in determining the total capacitance of the input/output. The total capacitance thus determined can be provided to a timing analysis tool (140), which uses the total capacitance of each input or output to generate a timing model for the circuit.

Abstract: The present invention describes a method and an apparatus for determining switching power consumption of global devices (e.g., repeaters, flops or the like) in an integrated circuit design during high-level design phase after the global routing for the integrated circuit is available. The clock cycle is divided into various timing intervals and the timing reports are generated for each cycle to determine a time-domain staggered distribution of each device's switching activity within a given timing interval. Each device's switching activity is analyzed within the given timing interval (or segment thereof). The power consumption is determined for each device that switches in the given timing interval.

Abstract: The present application describes various embodiments of a method and an apparatus for determining electromigration risks for signal nets in integrated circuits. A model for each one of the global nets connecting various circuit blocks in an integrated circuit is created using circuit blocks' timing model and detailed standard parasitic format representation (DSPF) of each global net. The final layout of the integrated circuit is not necessary to determine the electromigration risks. The models can be generated during the early stages of the design cycle once the DSPF of the global nets is available.

Abstract: The present application describes various embodiments of a method and an apparatus for determining electromigration risks for signal nets in integrated circuits. A model for each one of the global nets connecting various circuit blocks in an integrated circuit is created using circuit blocks' timing model and detailed standard parasitic format representation (DSPF) of each global net. The final layout of the integrated circuit is not necessary to determine the electromigration risks. The models can be generated during the early stages of the design cycle once the DSPF of the global nets is available.

Abstract: The present invention describes a method and an apparatus for determining switching power consumption of global devices (e.g., repeaters, flops or the like) in an integrated circuit design during high-level design phase after the global routing for the integrated circuit is available. The clock cycle is divided into various timing intervals and the timing reports are generated for each cycle to determine a time- domain staggered distribution of each device's switching activity within a given timing interval. Each device's switching activity is analyzed within the given timing interval (or segment thereof). The power consumption is determined for each device that switches in the given timing interval.

Abstract: The present invention describes a method and apparatus for placing flops in a complex circuit design. Initially, the method calculates a physical range for every net that requires a flop, within which the flop can be placed satisfying the timing requirement. After the physical range is defined, the method groups these flops and determines a block where these grouped flops can be placed. Grouping these flops into one block (flop station) can preserve a compact layout for the design. The flops are then connected to appropriate nets.

Abstract: The present invention describes a method and apparatus for placing flops in a complex circuit design. Initially, the method calculates a physical range for every net that requires a flop, within which the flop can be placed satisfying the timing requirement. After the physical range is defined, the method groups these flops and determines a block where these grouped flops can be placed. Grouping these flops into one block (flop station) can preserve a compact layout for the design. The flops are then connected to appropriate nets.

Abstract: The present invention describes a method and an apparatus for waiving noise violations during semiconductor integrated circuit design. The noise violations in a circuit area (e.g., an individual cell, block of cells or the like) are identified using a threshold look-up table. The threshold look-up table includes different thresholds for each circuit area. The threshold look-up table is generated using various cell related information including practical noise handling limits of each cell that can be higher than traditional noise limits. The information in the threshold look-up table helps eliminate benign noise violations and a new noise report is generated. The new noise report incorporates the practical noise handling capabilities of the cell under analysis and identifies actual noise violations in the semiconductor integrated circuit.

Abstract: In one aspect of the present invention, a method provides a connecting path diversion through an upper layer of an integrated circuit by alteration of a connecting path through a lower layer of the integrated circuit. This method enables a circuit path in an integrated circuit to be modified in an accessible layer for testing before the modified circuit path is incorporated in a redesigned integrated circuit design. In another aspect of the present invention, a modified multi-layer integrated circuit chip includes a connecting path formed in a lower layer and a substitute connecting path that is etched in the lower layer. Subsequently, the connecting path formed in the lower layer may be severed.

Abstract: In one aspect of the present invention, a method provides a connecting path diversion through an upper layer of an integrated circuit by alteration of a connecting path through a lower layer of the integrated circuit. This method enables a circuit path in an integrated circuit to be modified in an accessible layer for testing before the modified circuit path is incorporated in a redesigned integrated circuit design.

Abstract: In one aspect of the present invention, a method provides a connecting path diversion through an upper layer of an integrated circuit by alteration of a connecting path through a lower layer of the integrated circuit. This method enables a circuit path in an integrated circuit to be modified in an accessible layer for testing before the modified circuit path is incorporated in a redesigned integrated circuit design. In another aspect of the present invention, a modified multi-layer integrated circuit chip includes a connecting path formed in a lower layer and a substitute connecting path that is etched in the lower layer. Subsequently, the connecting path formed in the lower layer may be severed.