Cadence Design Systems, Inc.

Xin Gu

Nityanand Rai

Zhiyu Zeng

Hui Zheng

Anshu Mani

Avnish Varma

Parveen Khurana

Suketu Desai

Apurva Soni

Shivani Sharma

Bhuvnesh Kumar

Hailin Jiang

Rishabh

Babita C Verma

Yanfei Gu

Sanjeev Azad

Embodiments are generally directed to a hierarchical approach for performing simulation for PDNs that have integrated VRMs. According to certain aspects, embodiments include an approach that decouples the simulation for PDN and the simulation for VRM/PKG through PDN macromodeling. In these and other embodiments, the approach includes a SPICE-accurate simulation for the VRM part using a non-linear solver and using a linear solver for the PDN part, with minimal handshaking between them. For example, using a Backward Euler method having a fixed time step, at every simulation time interval, the linear solver sends reduced boundary currents to the non-linear solver. After the non-linear solver converges at the time interval, it sends boundary voltages back to the linear solver for determining voltages in the PDN part at the time interval.

Fast and accurate simulation for power delivery networks with integrated voltage regulators

The present disclosure relates to modeling the transient current of a partially simulated hierarchical gate-level electronic design. Embodiments may include providing a partially simulated hierarchical gate-level electronic design, wherein the design includes a design hierarchy having one or more leaf blocks associated therewith. Embodiments may also include identifying activity of sequential elements of the leaf blocks using simulation vectors, wherein the activity is used to estimate an amount of current associated with the sequential elements. Embodiments may further include computing an adaptive activity of a parent block of the leaf blocks, wherein the adaptive activity of the parent block corresponds to a weighted average of known activity of leaf blocks. Embodiments may also include generating an adaptive activity of a top block of the leaf blocks based upon the adaptive activity of the parent block and performing a mixed-mode simulation based upon the adaptive activity of the top block.

Current modeling process

In general, the present embodiments are directed to designing an electronic system such as an IC, and more particularly to techniques for analyzing a design for potential ESD instance failures. Embodiments allow for efficiently determining a potential ESD violation or non-violation status for a large number of instances, such as all the instances in a full chip design, by performing effective resistance analyses between all the instances and all the bumps and ESD protection devices in the design. These and other embodiments further allow for more detailed effective resistance analyses to be performed for potential failing instances.

Determining worst potential failure instances using full chip ESD analysis

The present embodiments relate to critical path aware voltage drop analysis. A method can include identifying a number of cell instances with largest individual power consumption values. The method can include identifying, by performing static timing analysis, a first number of circuit timing paths of an integrated circuit design with largest timing violations. The method can include identifying, by performing the static timing analysis, a second number of circuit timing paths of the integrated circuit design. Each of the second number of circuit timing paths has a timing violation and is formed by one or more of the identified number of cell instances. The method can include generating logic state toggle vectors by propagating logic states through the first and second numbers of circuit timing paths. The method can include performing voltage drop analysis on the integrated circuit design using the generated logic state toggle vectors.

Critical path aware voltage drop analysis of an integrated circuit

The present embodiments relate to generation of an interface model for performing a power analysis on a hierarchical integrated circuit design. According to some aspects, embodiments relate to a method of power analysis. The method can include partitioning an integrated circuit design into at least a first partition and a second partition sharing an interface with the first partition. The method can include generating a connectivity database of a signal net traversing from the first partition to the second partition across the first interface. The method can include determining a slew rate and a signal arrival time at the input pin of the destination cell, a capacitance load of the signal net, and one or more signal transitions and signal states on the signal net. The method can include calculating the power consumption of the circuit elements in the first partition using the connectivity database, and the determined information.

Interface modeling for power analysis of an integrated circuit

In general, the present embodiments are directed to designing an electronic system such as an IC, and more particularly to a design technique that can determine an optimal number and placement of ESD cells in a design for an IC. In embodiments, the technique includes determining an effective resistance criteria between a set of candidate ESD cells to the bumps/pads of the IC and finding a minimum set of ESD cells that covers all the bumps/pads. In embodiments, the technique is employed at the early stage of the design of the IC.

Electrostatic discharge cell placement using effective resistance

Disclosed herein are systems and methods to perform electrical analysis of a circuit design to verify electrical behavior and performance of the circuit design in a two-step process. Initially, a simulator transient analysis is performed on circuit blocks of a circuit design to obtain a current through each device path in each circuit block, and using the current obtained the IR drop and EM problems are examined to get EM-IR drop analysis. Next, a simulator transient analysis is performed on a top level circuit of a circuit design and current values generated in a first step to obtain EM-IR drop analysis for a full circuit design such that a circuit designer may debug, analyze and visualize various IR and EM value plots for circuit blocks and top level circuit of the circuit design together or separately.

Systems and methods for performing electromigration and voltage drop verification in electronic circuit designs

An improved approach is provided for determining differential voltages for driver and receiver pairs as a result of electrostatic discharge (ESD) events including identifying circuits of interest, re-characterizing the circuits of interest into a system for evaluating differential voltages, determining the differential voltages for ESD pin locations, and outputting results after iterating through all the ESD pin locations. In some embodiments, re-characterizing may include performing a resistance only extraction of a net, attaching a resistance to any node in the circuit and to ground, formulating a conductance matrix and distributing the total current I as source points. In some embodiments, determining differential voltages for ESD pin locations may include, stamping a first ESD pin location with a total current, solving for the system using previously computed values, mapping the driver and receiver pairs to the nodes in the system, computing the differential voltage, and recording the lowest differential voltage.

Method and system for efficiently determining differential voltages for electrostatic discharge simulations

The present disclosure relates to a system and method for determining an effective electrical resistance in an electronic circuit design. Embodiments may include receiving, at one or more computing devices, an electronic circuit design and identifying one or more features associated with the electronic circuit design. Embodiments may also include performing a resistance only extraction of a circuit net associated with the electronic circuit design and identifying at least two node locations from the electronic circuit as one or more port nodes. Embodiments may further include reducing the resistance only extraction to an equivalent circuit including only the port nodes and attaching a high-resistance ground voltage source to at least one of the port nodes of the reduced equivalent circuit. Embodiments may also include generating a conductance matrix, based upon, at least in part, the reduced equivalent circuit.

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Austin, TX, United States of America

Xin Gu