Abstract: Some embodiments provide a method of designing an integrated circuit (IC). The design is expressed as a graph that includes several nodes that represent several IC components. The nodes include a first set of nodes that represent a set of clocked elements. The method creates a second set of nodes by removing all nodes in the first set from the nodes that represent the IC components. The method identifies a set of edges that connect two nodes in the second set without encompassing a third node in the second set. The method assigns an event time to each node in the second set. The method assigns a cost function based on the event times of the nodes connected by each edge and the number of nodes in the first set encompassed by each edge. The method optimizes the cost function and places the components based on the cost function optimization.

Abstract: Systems and techniques are described for performing numerical delay, area, and leakage power optimization on a circuit design. During operation, an embodiment can iteratively perform at least the following set of operations in a loop, wherein in each iteration a current threshold voltage value is progressively decreased: (a) perform numerical delay optimization on the circuit design using a numerical delay model that is generated using gates in a technology library whose threshold voltages are equal to the current threshold voltage; (b) perform a total negative slack based buffering optimization on the circuit design; and (c) perform a worst negative slack touchup optimization on the circuit design that uses gates whose threshold voltages are greater than or equal to the current threshold voltage. Next, the embodiment can perform combined area and leakage power optimization on the circuit design. The embodiment can then perform multiple iterations of worst negative slack touchup optimization.

Abstract: Systems and methods for modeling multi-patterning variability with statistical timing analysis during IC fabrication are described. The method may be provided implemented in a computer infrastructure having computer executable code tangibly embodied on a computer readable storage medium having programming instructions operable to define at least one source of variation in an integrated circuit design. The programming instructions further operable to model the at least one source of variation for at least two patterns in at least one level of the integrated circuit design as at least two sources of variability respectively.

Abstract: Methods and systems for excluding library cells are described. Some embodiments receive a generic logical effort value and optionally a generic parasitic delay value for a timing arc of a library cell type. Next, library cells of the library cell type are excluded whose specific logical effort values for the timing arc are greater than the generic logical effort value by more than a first threshold and/or optionally whose specific parasitic delay values for the timing arc are greater than the generic parasitic delay value by more than a second threshold. A new generic logical effort value and optionally a new generic parasitic delay value can be determined based on at least some of the remaining library cells. The process of excluding library cells and determining new generic logical effort values and optionally new generic parasitic delay values can be performed iteratively.

Abstract: A standard cell library is disclosed. The standard cell library contains cells wherein at least one transistor in at least one cell is annotated for gate length biasing. Gate length biasing includes the modification of the gate length, so as to change the speed or power consumption of the modified gate length. The standard cell library is one used in the manufacturing of semiconductor devices (e.g., that result as semiconductor chips), by way of fabricating features defined on one or more layouts of geometric shapes. The annotations serve to identify which ones of the transistor gate features are to be modified before using the geometric shapes for manufacturing the semiconductor device.

Abstract: One embodiment sets forth a timing calibration technique for on-chip source-synchronous, complementary metal-oxide-semiconductor (CMOS) repeater-based interconnect. Two transition patterns may be applied to calibrate the delay of an on-chip data or clock wire. Calibration logic is configured to apply the transition patterns and then trim the delays of the clock and data wires based on captured calibration patterns. The trimming adjusts the delay of the clock and data wires using a configurable delay circuit. Timing errors may be caused by crosstalk, power-supply-induced jitter (PSIJ), or wire delay variation due to transistor and wire metallization mismatch. Chip yields may be improved by reducing the occurrence of timing errors due to mismatched delays between different wires of an on-chip interconnect.

Abstract: A mechanism is provided in a data processing system for timing-driven routing for noise reduction in integrated circuit design. Responsive to performing timing driving routing on an integrated circuit design, the mechanism identifies a set of noise-critical nets in the integrated circuit design. The mechanism performs timing driven routing on the integrated circuit design with noise constraints based on the set of noise-critical nets.

Abstract: In one embodiment of the invention, a method includes partitioning an integrated circuit design into a hierarchy of a top level and a plurality of partitions, wherein the top level includes a top level netlist and each partition includes a partition netlist; receiving data path timing budgets and clock path timing budgets for each of the plurality of partitions of the integrated circuit design; and generating a timing budget model of each partition in response to the respective data path timing budgets and clock path timing budgets, wherein each timing budget model includes an intra-partition clock timing constraint for each respective partition for independent implementation of the top level.

Abstract: In one embodiment of the invention, a method of logic synthesis is disclosed. The method includes generating a plurality of design architecture alternatives for circuit logic of a data path cluster; saving the plurality of design architecture alternatives; and evaluating the plurality of design architecture alternatives in response to design constraints to select a preferred design architecture.

Abstract: A system, method, and computer program product for converting a design from edge-triggered docking to two-phase non-overlapping clocking is disclosed. The method includes the steps of replacing an edge-triggered flip-flop circuit that is coupled to a combinational logic circuit with a pair of latches including a first latch circuit and a second latch circuit and determining a midpoint of the combinational logic circuit based on timing information. The second latch circuit is propagated to a midpoint of the combinational logic circuit and two-phase non-overlapping clock signals are provided to the pair of latches.

Abstract: Optimized buffer placement is provided based on timing and capacitance assertions in a functional chip unit including a single source and multiple macros, each having a sink. Placement of the source and macros with the sinks is pre-designed and buffers are placed in branches connecting the source with the multiple sinks. An estimated slack is calculated for each branch, the branches are arranged according to the calculated slack, decoupling buffers are inserted in all branches except the most critical branch(es), the most critical branch(es) are globally routed and slew conditions are fixed within this branch, and at least one next branch is globally routed and slew conditions are fixed therein.

Abstract: Circuit simulation can be performed on digital, analog, and mixed signal types of circuitry. Phases of operation are identified for a circuit and transient behavior is analyzed. Multiple time points are identified and the circuit is replicated for those time points with evaluation of the circuitry performed at those various time points. Simultaneous optimization is performed across the time points. Transistors and other devices can have their lengths, widths, and number of fingers optimized. Simulation can include determining Kirchhoff current law equations for various nodes within the circuit. Equations describing device operation can include non-convex signomial equations and convex polynomial equations.

Abstract: A computer-implemented method of determining an attribute of a circuit includes using a computationally expensive technique to simulate the attribute (such as timing delay or slew) of a portion of the circuit, at predetermined values of various parameters (e.g. nominal values of channel length or metal width), to obtain at least a first value of the attribute. The method also uses a computationally inexpensive technique to estimate the same attribute, thereby to obtain at least a second value which is less accurate than the first value. Then the computationally inexpensive technique is repeatedly used on other values of the parameter(s), to obtain a number of additional second values of the attribute. Applying to the additional second values, a function obtained by calibrating the at least one second value to the at least one first value, can yield calibrated estimates very quickly, which represent the attribute's variation relatively accurately.

Abstract: A method for performing latency optimization on a system design to be implemented on a target device includes inserting a variable latency indicator in the system design at a place where latency can be varied. The system design includes pipeline registers at the place where the variable latency indicator is inserted. Latency optimization is then automatically performed on the system design, during a computer aided design flow performed by an electronic Design Automation (EDA) tool, by varying the number of the pipeline registers at the variable latency indicator to obtain optimized latency without affecting system performance of the system design.

Abstract: A method comprising placing elements in a layout, performing clock tree synthesis, and performing routing. The method further comprising, in parallel with one of the clock tree synthesis or the routing, performing a footprint based optimization, substituting a footprint equivalent element in a path based on a timing slack of the path.

Abstract: An automated method of modifying a semiconductor chip design includes creating a timing analysis of said semiconductor chip design, identifying a plurality of gates in said semiconductor chip design which have either too fast a rising edge or falling edge, for each gate in said plurality of gates adding a stacked transistor to provide delay to the rising or falling edge of the gate. A design structure tangibly embodied in a machine readable medium for designing, manufacturing, or testing an integrated circuit, the design structure includes a CMOS device having a first transistor with a first input, a pair of stacked transistors having a second input, and an output.

Abstract: A method for modeling jitter includes generating a first delay-impacting parameter function for a first signal and a second delay-impacting parameter function for a second signal. A first delay per element function is generated from the first delay-impacting parameter function and a second delay per element function from the second delay-impacting parameter function. A difference in path delay from the first delay per element function and the second delay per element function is identified.

Abstract: A first signal is transmitted through a first path. A computing device determines a signal propagation time of the first signal. The computing device transmits a second signal through a second path, wherein the second path includes the second signal traversing across at least one interconnecting structure. The computing device determines a signal propagation time of the second signal. The computing device determines a propagation time difference between the signal propagation time of the first signal and the signal propagation time of the second signal. The computing device adjusts a clock based on the determined propagation time difference.

Abstract: A method comprises providing a non-transitory, machine-readable storage medium storing a partial netlist of at least a portion of a previously taped-out integrated circuit (IC) layout, representing a set of photomasks for fabricating an IC having the IC layout such that the IC meets a first specification value. A computer identifies a proper subset of a plurality of first devices in the IC layout, such that replacement of the proper subset of the first devices by second devices in a revised IC layout satisfies a second specification value different from the first specification value. At least one layout mask is generated and stored in at least one non-transitory machine readable storage medium, accessible by a tool for forming at least one additional photomask, such that the set of photomasks and the at least one additional photomask are usable to fabricate an IC according to the revised IC layout.

Abstract: A method of pipelining a data path in an integrated circuit is described. The method comprises receiving a circuit design to be implemented in the integrated circuit device; providing a placement of the circuit design in the integrated circuit device; identifying a most critical path of the placement; adding pipeline registers to the most critical path; and adding pipeline registers to all paths that are parallel to the most critical path. A computer program product for pipelining a data path in an integrated circuit is also described.

Abstract: A hybrid clock distribution system uses a distribution fabric to distribute clock signals across longer physical distances and local sub-distribution networks to distribute clock signals more locally and to implement logic functions such as clock gating. A set of tap drivers connect the distribution fabric to the sub-distribution networks. A design tool automatically generates and places the set of tap drivers.

Abstract: An on-chip timing slack monitor that measures timing slack at the end of a critical path includes a master-slave flip-flop having a tap on the Q output of the master and a logic module coupled to the flip-flop for producing a pulse whose width is a function of the slack. A pulse width shrinking delay line removes glitches on the flip-flop output and, in combination with a digital integrator and counter, also performs a time to digital conversion operation for determining a value for timing path slack. The determined value is used by a decision module for yield analysis. The monitor can discriminate a glitch from a slack pulse at the flip-flop output for any width of glitch up to one-half of a clock cycle.

Abstract: A system, process, etc. according to some embodiments, which includes operations that include selecting one of a plurality of solutions (“selected solution”) for optimization of an integrated circuit design during physical synthesis. The operations can further include performing on the selected solution a fast evaluation of a specific metric without updating design documents (e.g., without updating a netlist or metric map). If the evaluation of the specific metric is non-satisfactory, then the candidate solution is rejected. If the evaluation of the specific metric is satisfactory, then a design document is updated and a full evaluation of the specific metric (and other metrics) can be performed.

Abstract: The technological fabrication of the integrated circuit includes a fabrication of the integrated circuit in a reduced technological version of a native technology including at least a first dimensional compensation applied to the reduced channel length and to the reduced channel width of each transistor originating from a transistor, referred to as a “minimum transistor”, designed in the native technology and having in this native technology an initial channel length equal to a minimum length for the native technology and an initial channel width equal to a minimum width for the native technology. The fabrication obtains a transistor having a channel length equal, to a given precision, to the initial channel length and a channel width equal, to a given precision, to the initial channel width.

Abstract: A system and method for expeditious operational timing signoff of a circuit design through a timing analysis and subsequent corrective or remedial optimization is performed with the goal of correlating timing between the physical implementation corrective optimizer module and the timing analysis module to reduce iterations therebetween. A physical optimizer in the correction module is imparted with knowledge of the physical implementation of the design to allow for legal, non-conflicting placement of corrective buffers or resizing of gates in accordance with the physical implementation data of the circuit design.

Abstract: A hierarchical interface module includes an assessment unit configured to identify a hierarchical implementation incompatibility of an integrated circuit (IC) partitioned block. Additionally, the hierarchical interface module includes an interface unit configured to substitute a directly registered hierarchical interface structure for the hierarchical implementation incompatibility of the IC partitioned block. A method of interfacing hierarchically and a hierarchical implementation system are also included.

Abstract: A standard cell library is disclosed. The standard cell library contains cells wherein at least one transistor in at least one cell is annotated for gate length biasing. Gate length biasing includes the modification of the gate length, so as to change the speed or power consumption of the modified gate length. The standard cell library is one used in the manufacturing of semiconductor devices (e.g., that result as semiconductor chips), by way of fabricating features defined on one or more layouts of geometric shapes. The annotations serve to identify which ones of the transistor gate features are to be modified before using the geometric shapes for manufacturing the semiconductor device.

Abstract: A semiconductor device includes: a plurality of line features including at least one real feature which includes a gate electrode portion, and at least one dummy feature. Two of multiple ones of the dummy feature, and at least one of the line features interposed between the two dummy features and including the at least one real feature form parallel running line features which are evenly spaced. The parallel running line features have an identical width, and line end portions of the parallel running line features are substantially flush. Line end portion uniformization dummy features are formed on extensions of the line end portions of the parallel running line features. The line end portion uniformization dummy features include a plurality of linear features each having a same width as each of the line features and spaced at intervals equal to an interval between each adjacent pair of the line features.

Abstract: Methods and apparatuses are described for optimizing local clock skew, and/or for synthesizing clock trees in an incremental fashion. For optimizing local clock skew, the circuit design can be partitioned into clock skew groups. Next, for each clock skew group, an initial clock tree can be constructed that substantially minimizes worst case clock skew in the clock skew group, and then the initial clock tree can be further optimized by substantially minimizing worst case local clock skew in the clock skew group. For performing incremental clock tree synthesis, a portion of a clock tree in the circuit design can be selected based on a set of modifications to the circuit design. Next, a new clock tree can be determined to replace the selected portion of the clock tree. The circuit design can then be modified by replacing the selected portion of the clock tree with the new clock tree.

Abstract: A system and method optimizes hardware description code generated from a graphical program or model automatically. The system may include a streaming optimizer, and a delay balancing engine. The streaming optimizer transforms one or more vector data paths in the source model to scalar data paths or to a smaller-sized vector data paths. The streaming optimizer may also configure portions of the modified model to execute at a faster rate. The delay balancing engine may examine the modified model to determine whether any delays or latencies have been introduced. If so, the delay balancing engine may insert one or more blocks into the modified model to correct for any data path misalignment caused by the introduction of the delays or latencies. A validation model, a report, or hardware description code that utilizes fewer hardware resources may be generated from the modified model.

Abstract: An approach for methodology enabling a verification of IC designs that compensates for degraded performance due to a physical placement, particularly a stacked physical placement is disclosed. A set of stacked devices from a plurality of devices in an IC design is determined. One or more instance parameters indicating a physical placement of a device in the set is determined. A compensation metric indicating one or more electrical characteristics of a device in the set is determined based on the one or more instance parameters.

Abstract: A system and method are provided for generating a structurally-aware timing model for operation of a predetermined circuit design. The timing model is generated to have a plurality of timing arcs representing timing characteristics of the circuit design. Additionally, terminal pairs of the circuit design are evaluated to determine characteristic structural weights for selected paths through the circuit design. The structurally-aware timing model may then be incorporated into a top-level hierarchical circuit design for timing analyses and pessimism removal to arrive at realistic timing characteristics. The structural weights are particularly helpful in an AOCV-type pessimism removal post-process.

Abstract: A method of configuring an integrated circuit device with a user logic design includes analyzing the user logic design to identify timing requirements of paths within the user logic design, determining latency requirements along those paths, routing the user logic design based on availability of storage elements for incorporation into those paths to satisfy the latency requirements, and retiming the user logic design following that routing by incorporating at least some of the storage elements.

Abstract: A system and methods for metastability verification of an integrated circuit design are provided. An IC design is received and the source-to-destination paths of the IC design are determined. For each of the determined source-to-destination paths, it is determined whether the corresponding source is synchronized. For each source its respective synchronized or unsynchronized result is stored and a report is generated for each source describing whether it is synchronized or unsynchronized. The system may be at least a portion of a computer aided design (CAD) system.

Abstract: The present patent document relates to a method and apparatus for an automatic clock to enable conversion for FPGA-based prototyping systems. A library or netlist is provided having a plurality of state elements of a chip design to be prototyped by a user. The chip design can have dozens of different user clocks and clock islands using these different user clocks. The state elements of an element library or netlist are converted to a circuit having one or more state elements and other logic that receive both a user clock as well as a fast global clock. With the disclosed transformations, the functionality of the original state element is maintained, and a single or low number of global clocks can be distributed in an FPGA of the prototype with user clocks generated locally on the FPGA.

Abstract: Systems and techniques are described for estimating optimal gate sizes in a circuit design using numerical delay models of cells and cell types in a technology library. Gate sizes are optimized in the circuit design in a reverse-levelized processing order. Gates that are at the same level in the reverse-levelized processing order, and whose inputs are electrically connected to the same driver output are optimized together. A closed-form expression is used to determine the optimized size for each gate in a set of gates that are optimized together. Some embodiments perform multiple optimization iterations, wherein in each optimization iteration all of the gates in the circuit design are processed in the reverse-levelized processing order. The iterative optimization process terminates when one or more termination conditions are met.

Abstract: A method of optimizing power and timing for an integrated circuit (IC) chip, which uses an IC technology that exhibits temperature inversion, by modifying a voltage supplied to the IC chip, while meeting power consumption and timing delay performances across lower and higher temperature ranges. A high voltage is selected that meets a closed timing analysis across a full temperature range to meet a timing performance and a low voltage is selected to meet the timing performance and the power performance across a lower temperature range to a temperature cut point in the higher temperature range. The IC chip is turned on at the high voltage and the high voltage is lowered to the low voltage when the temperature cut point is exceeded to meet the power performance while maintaining the timing performance.

Abstract: The invention provides a method for performing statistical static timing analysis using a novel on-chip variation model, referred to as Sensitivity-based Complex Statistical On-Chip Variation (SCS-OCV). SCS-OCV introduces complex variation concept to resolve the blocking technical issue of combining local random variations, enabling accurate calculation of statistical variations with correlations, such as common-path pessimism removal (CPPR). SCS-OCV proposes practical statistical min/max operations for random variations that can guarantee pessimism at nominal and targeted N-sigma corner, and extends the method to handle complex variations, enabling graph-based full arrival/required time propagation under variable compaction. SCS-OCV provides a statistical corner evaluation method for complex random variables that can transform vector-based parametric timing information to the single-value corner-based timing report, and based on the method derives equations to bridge POCV/SSTA with LOCV.

Abstract: Systems and techniques are described for automatically generating clock tree synthesis (CTS) exceptions. The process can use on one or more criteria to identify sequential circuit elements that can be ignored during clock skew minimization. For example, the process can identify sequential circuit elements whose clock skew cannot be balanced with other sequential circuit elements due to structural reasons, identify sequential timing elements that do not have a timing relationship with other sequential timing elements in the clock tree, and/or identify sequential circuit elements whose data pins have a sufficiently large slack so that clock skew is not expected to cause timing violations at any of the data pins. Next, the process can generate clock tree exceptions based on the identified sequential circuit elements.

Abstract: A method of reducing current leakage in unused circuits performed during semiconductor fabrication and a semiconductor device or integrated circuit thereby formed. The method involves modifying a characteristic of at least one idle circuit that is unused in a product variant, to inhibit the circuit and reduce current leakage therefrom upon powering as well as during operation. The method can substantially increase the Vt (threshold voltage) of all transistors of a given type, such as all N-type transistors or all P-type transistors. The method is also suitable for controlling other transistor parameters, such as transistor channel length, as well as other active elements, such as N-type resistors or P-type resistors, in unused circuits which affect leakage current as well as for other unused circuits, such as a high Vt circuit, a standard Vt circuit, a low Vt circuit, and an SRAM cell Vt circuit.

Abstract: Techniques for generating timing constraints for an integrated circuit including a clock tree network are described. The techniques may be associated with a clock tree synthesis tool that receives a design of the integrated circuit and generates a clock tree network including a plurality of clocked components of the integrated circuit. The constraints may be generated as a function of the duration of propagation of a data signal from a transmitting clocked component coupled to a receiving clocked component.

Abstract: Methods determine temperature and voltage relationships for integrated circuit library elements to produce a continuous temperature-voltage function. Some of the library elements can be used or combined to form an integrated circuit design. Further, the performance characteristics for integrated circuit chips produced according to the integrated circuit design can be defined, such performance characteristics include an operating temperature range, etc. The continuous temperature-voltage function is applied to the performance characteristics to determine a plurality of temperature/voltage combinations for the integrated circuit chips. Each of the temperature/voltage combinations comprises an operating voltage for each operating temperature within the operating temperature range of the integrated circuit chips. Next, the integrated circuit chips are produced according to the integrated circuit design. The temperature/voltage combinations are recorded in memory of the integrated circuit chips.

Abstract: A global optimization method to synthesize and balance the clock systems in a multimode, multi-corner, and multi-domain design environment is described. The method builds a graph representation for a clock network. The method determines an optimal clock network balancing solution for the clock network by applying linear programming to the graph. To apply linear programming to the graph, the method generates a set of constraints for the graph and determines a proper insertion delay for each edge of the graph by solving for a minimal skew based on the set of constraints. The method implements the optimal clock network balancing solution.

Abstract: An electronic design automation (EDA) tool alters a user's netlist to provide timing success for distribution of asynchronous signals. Distribution networks are used with the addition of pipeline registers before and/or after the distribution buffer. Or, a tree of pipeline registers is inserted between the asynchronous source and the destination registers. Or, any number of distribution networks are stitched together and pipeline stages may be inserted before and/or after each distribution buffer. Or, beneficial skew is utilized by introducing a delay component that skews a clock signal. The skewed clock signal drives a pipeline register that is inserted before a distribution buffer in order to improve timing margin. Any of various compilation techniques may be used within the EDA tool to solve the problem of distributing high-speed, high-fanout asynchronous signals.

Abstract: An embodiment of the present invention is a computer program product for providing an adjusted electronic representation of an integrated circuit layout. The computer program product has a medium with a computer program embodied thereon. Further, the computer program comprises computer program code for providing full node cells from a full node netlist, computer program code for scaling the full node cells to provide shrink node cells, computer program code for providing a timing performance of the full node cells and the shrink node cells, computer program code for comparing the timing performance of the full node cells to the timing performance of the shrink node cells, and computer program code for providing a first netlist.

Abstract: A first assembly of critical cells is to be monitored. An equivalent capacitance of output cells coupled to the critical path is determined. Logic level inputs of the critical cells for signal propagation are also determined. A second assembly of control logic cells is provided which copies the first assembly in terms of number of cells, type of cells and cell connection such that each of the control cells is a homolog of a corresponding critical cell. Charge cells are provided at the outputs of the control cells having an equivalent capacitance in accordance with the determined capacitance of the output cells. For each control cell, logic levels are asserted in accordance with the determined configuration of the critical path. A signal generator applies a signal the input of the second assembly and a signal receiver is coupled to the output of the second assembly.

Abstract: A power supply circuit design system according to an exemplary aspect of the invention includes: a power supply voltage fluctuation deriving means for deriving a power supply voltage fluctuation characteristic as a voltage fluctuation characteristic in a semiconductor integrated circuit on the basis of design information about a power supply circuit for connecting the semiconductor integrated circuit and other components mounted on a substrate; a determination reference database including a power supply voltage fluctuation condition as a condition for which the power supply voltage fluctuation characteristic is allowed in the power supply circuit, and a change indicator for at least one of a circuit structure and operation of the semiconductor integrated circuit; a power supply voltage fluctuation determination means for comparing the power supply voltage fluctuation characteristic and the power supply voltage fluctuation condition, and determining whether the power supply voltage fluctuation characteristic s

Abstract: Devices, systems and methods of this disclosure can provide integrated circuit devices operating above their specified operating temperate. The integrated circuit device can include functional blocks with power down circuitry and functional test blocks with built in self-test capabilities (BIST). The functional blocks can be implemented with timing constraint values to provide a timing margin for the device above a specified operation temperature. The functional test blocks can be implemented with timing constraint values that result in BIST failure when the device is operated above the specified operation temperature. As the temperature of the device rises above the operating temperature the functional test blocks can fail BIST prior to loss of functionality of the functional blocks. Upon BIST failure of the functional test blocks, circuitry in the functional blocks can be powered down to facilitate continued operation of the device with reduced functionality.

Abstract: A system and method for automatically modifying a first layout of a circuit. The first layout may describe a plurality of layers used in a fabrication process to manufacture the circuit. When performed, the fabrication process may result in a vertical electrical connection between two of the layers. However, the vertical electrical connection may not be directly specified by the first layout. The system and method may operate to apply a set of rules to the first layout to automatically generate a modified layout directly specifying a vertical electrical connection between the two layers. The set of rules may be based on knowledge of the fabrication process, and may be designed to modify the geometry of the first layout to more closely model the real geometry of the circuit that will result from the fabrication process. The modified layout may enable an electromagnetic (EM) simulation of the circuit to be accurately performed.

Abstract: A method for use in electronic design software efficiently and optimally produces minimized or reduced register flip flop area or number of registers/flip flops in a VLSI circuit design without changing circuit timing or functionality. The method dynamically generates constraints; maintains the generated constraints as a regular tree; and incrementally relocates registers/flip flops and/or the number of registers/flip flops in the circuit design.