Product Documentation
Spectre Classic Simulator, Spectre APS, Spectre X, Spectre XPS, Spectre FMC Analysis, and Legato Reliability Solution User Guide
Product Version 23.1, September 2023


Preface

The Spectre® simulation platform contains a set of simulation technologies for circuit design and verification. It supports multiple netlist formats, all standard device models, a large variety of large and small signal analyses, design checking features, a large set of output formats, and advanced analyses like EMIR, RF, and device reliability.

Different simulation engines are integrated into the platform – Spectre SPICE engine, Spectre Accelerated Parallel Simulator (APS) for high-precision SPICE and scalable multi-core simulation performance, Spectre X Simulator for high-performance, high-capacity simulation to handle the largest pre- and post-layout designs with analog accuracy, which also includes extensive distribution capabilities designed to maximize a cloud or server farm use model, Spectre Extensive Partitioning Simulator (Spectre XPS), an advanced FastSPICE engine, which provides high performance simulation for SRAM, DRAM, and flash designs, and the Spectre FX simulator, the next-generation FastSPICE simulator from Cadence. With Spectre AMS Designer, you can mix any of the above analog solvers with the Cadence® Xceliumâ„¢ Parallel Logic Simulator.

Besides the comprehensive set of basic analyses, the Spectre circuit simulator and Spectre X provide the RF simulation capabilities to verify RF and communication circuits, such as mixers, oscillators, sample holds and switched-capacitor filters.

Additional information on the Spectre RF simulation option is covered in the Spectre Circuit Simulator and Accelerated Parallel Simulator RF Analysis User Guide.

This user guide assumes that you are familiar with:

Licensing

Cadence offers both ala carte pricing plus a unique multi-mode simulation (MMSIM) license that can enable the Spectre simulation platform. Spectre circuit simulator, Spectre APS, Spectre® XPS, Spectre® X, and Spectre® FX are the base products. The features provided in these base products are listed in Table A-1, Table A-2, and Table A-3. In addition, the options available across each of these base products are listed in Table A-4. Both the base products and the options are accessible using Spectre MMSIM tokens.

For details on Spectre FX license requirements, see Spectre FX Circuit Simulator User Guide.

For additional details on licensing, pricing and packaging contact your account manager.

Table A-1 Spectre® Circuit Simulator

Spectre Circuit Simulator Features

DC, small-signal analyses and transient

Monte Carlo, DC mismatch, Parametric sweep

Transient noise analysis

Reliability analysis

Encryption

AHDL Linter

Built-in Measurement Description Language (MDL)

MMSIM Toolbox for MATLAB® from The MathWorks

Cadence Proprietary Agemos Model

Cosimulation with Simulink® from The MathWorks

Broadband SPICE (BBSpice)

Table A-2 Spectre® Accelerated Parallel Simulator (Spectre APS)

Spectre APS Single-Core Features

All analyses and features in Spectre Circuit Simulator

Parasitic Reduction

Parasitic Stitching

Postlayout Simulation

Static and Dynamic Circuit Checks

Table A-3 Spectre eXtensive Partitioning Simulator (Spectre XPS)

Dynamic and Power Simulation

Static and Dynamic Circuit Checks

Variation Analysis

Postlayout Simulation

AHDL Linter

Table A-4 Spectre Options for Spectre, Spectre APS, Spectre XPS, Spectre X, and Spectre FX

Spectre Option Description

Spectre(R) RF option

Enables RF analysis with Spectre, Spectre APS, and Spectre X simulator

Spectre CPU Accelerator option

Enables multi-core simulation up to 64 cores with Spectre APS and Spectre XPS base products on a single machine or across a cluster of machines (distributed processing). In addition, it enables EMIR analysis with Spectre APS base product and Spectre Power option.

To run multi-threading on 4 cores, you need 1 Spectre CPU Accelerator option. 2 Spectre CPU Accelerator options are required to perform multi-threading computation on 16 cores.

Spectre X Multi-Core Option

Enables multi-core simulation up to 512 cores with Spectre X base product on a single machine or across a cluster of machines (distributed processing).

To run multi-threading on 4 CPUs, you need 1 Spectre X Multi-Core Option. 2 Spectre X Multi-Core Options are required to perform multi-threading computation on 16 CPUs. 3 Spectre X Multi-Core Options are required to perform multi-threading computation on 64 CPUs and 4 Spectre X Multi-Core Options are required to perform multi-threading computation on 128 CPUs.

Spectre Power option

Enables EMIR analysis with Spectre X base product. It also enables EMIR analysis with Spectre APS base product and the Spectre CPU Accelerator option.

This option is not available with Spectre base product.

Spectre Characterization Simulator option

Provides you access to the Spectre simulators for characterization simulation jobs only. It is only available as an option to Liberate characterization family of products. Please contact your account representative for further details.

For details on the capabilities and features offered with the Spectre RF analysis option, refer to the Spectre Circuit Simulator and Accelerated Parallel Simulator RF Analysis User Guide.

License Requirement for Spectre FMC

The Spectre FMC Option license enables Spectre FMC Analysis. You can also use MMSIM tokens. Contact Cadence Customer Support for more details.

Legato Reliability Solution License

The Legato reliability solution license, which is a pack of 6 tokens (that are not the same as MMSIM tokens), is required to run the following reliability features. Contact Cadence Customer Support for more details.

Table A-5 Legato Reliability Tokens

Feature Number of tokens Required Functionality

Analog Fault Simulation

3

Spectre transient fault analysis and Spectre direct fault analysis

Fault Generation

0

info what=bridges|opens|dhe

Does not check out the license; however, checks for the availability of the license.

spectre_ddmrpt

0

spectre_ddmrpt

Does not check out the license; however, checks for the availability of the license.

spectre_fsrpt

0

spectre_fsrpt

Does not check out the license; however, checks for the availability of the license.

Electrothermal Simulation

2

Spectre electrothermal simulation

Electrothermal simulation requires a Celsius_Thermal license during Spectre thermal extraction, and 2 legato tokens during the remaining electrothermal simulation. The Celsius_Thermal license is released after thermal extraction is completed and then the 2 legato tokens are checked out.

RelXpert

4

RelXpert simulation

Product 33580: Spectre® RelXpert Reliability license is still available in SPECTRE 20.1.

Spectre self-heating

1

Spectre self-heating analysis

Spectre self-heating + Aging analysis

1

Spectre self-heating and Aging analysis

Monte Carlo + Aging analysis

1

Monte Carlo and Aging analysis

RF reliability analysis

1

Spectre RF reliability analysis, such as pss, pnoise, hb, hbnoise, sp, pac, and pxf.

Spectre reliability with XPS S mode

1

Spectre reliability analysis with XPS SPICE mode

STB reliability analysis

1

Spectre STB reliability analysis

The Legato reliability solution can also be run with MMSIM tokens.

License Checkout Order

The order in which the license features are checked out is determined either by a default checkout order or by a customized order that can be defined using the +lorder option. Spectre, Spectre APS, Spectre XPS, and Spectre X check for a license in the order specified using the +lorder licenseList option. Note that mixing of ala carte license and Spectre MMSIM tokens is not allowed.

To make it easier to specify license names with the +lorder option, a representative mnemonic license has been provided, as shown in Table A-6.

Table A-6 Mnemonic License Names and Corresponding License Feature

MMSIM

Virtuoso_Multi_mode_Simulation, Virtuoso_APS_MMSIM_Lk, Virtuoso_XPS_MMSIM_Lk Spectre_X_MMSIM_Lk

PRODUCT

Virtuoso_Spectre , Virtuoso_Acceler_Parallel_sc, Spectre_XPS, spectre_X_sc

You can specify the following for licenseList:

+lorder PRODUCT - Spectre attempts to check out the product and options combination licenses only. If the licenses are not available, Spectre generates an error.

+lorder MMSIM - Spectre attempts to check out the Virtuoso_Multi_mode_Simulation (Spectre MMSIM) tokens only.

+lorder PRODUCT:MMSIM - Spectre attempts to check out product licenses first. If product licenses are not available, Spectre attempts to check out Spectre MMSIM tokens.

+lorder MMSIM:PRODUCT - Spectre attempts to check out Spectre MMSIM tokens first. If the tokens are not available Spectre attempts to check out product licenses.

The default license checkout order for features in Spectre, Spectre APS, Spectre XPS, and Spectre X base products is PRODUCT:MMSIM.

Using License Queuing

You can turn on license queuing by using the lqtimeout command line option:

spectre +lqtimeout time_in_seconds

If a license is not available when you begin a simulation job, the Spectre circuit simulator waits in queue for a license for the specified time. If you specify the value 0 for this option, the Spectre circuit simulator waits indefinitely for a license. The lqtimeout option has no default value for the standalone Spectre circuit simulator. If you invoke Spectre through the Analog Design Environment, the default value for lqtimeout is 900 seconds. You can use the lqsleep option to specify the interval (in seconds) at which the Spectre circuit simulator should check for license availability. The default value for lqsleep is 30 seconds.

spectre +lqsleep interval

For more information on any of the above options, see spectre -h.

Suspending and Resuming Licenses

You can direct Spectre to release licenses when suspending a simulation job. This feature is aimed for users of simulation farms, where the licenses in use by a group of lower priority jobs may be needed for a group of higher priority jobs.

To enable this feature, simply start Spectre with the +lsuspend command line option. Press ctrl+z to suspend the simulation run and release the licenses. All licenses are checked in. To resume simulation, press fg. These keystrokes may not work if you have changed the default key bindings. You can also use the kill command to suspend and resume the simulation. You can suspend a simulation with kill -s TSTP <pid>. To resume the simulation, type kill -s CONT <pid>.

When distributing simulation jobs with a Distributed Resource Management System (DRMS), suspend the simulation and release licenses by sending the TSTP signal. Resume jobs by sending the CONT signal."

For information on tracking token licensing, see the Virtuoso® Software Licensing and Configuration Guide.

In Virtuoso® ADE Product Suite, the lqtimeout and lqsleep options are controlled by the following options:

spectre.envOpts lsuspend boolean t
spectre.envOpts licQueueTimeOut string "900"
spectre.envOpts licQueueSleep string "30"

Related Documents for Spectre

This user guide contains information about the functionality. The following documents provide more information about Spectre RF and related products.

Third Party Tools

To view any .swf multimedia files, you need:

Typographic and Syntax Conventions

This list describes the syntax conventions used for the Spectre circuit simulator.

literal

Nonitalic words indicate keywords that you must enter literally. These keywords represent command (function, routine) or option names, filenames and paths, and any other sort of type-in commands.

argument

Words in italics indicate user-defined arguments for which you must substitute a name or a value. (The characters before the underscore (_) in the word indicate the data types that this argument can take. Names are case sensitive.

|

Vertical bars (OR-bars) separate possible choices for a single argument. They take precedence over any other character.

[ ]

Brackets denote optional arguments. When used with OR-bars, they enclose a list of choices. You can choose one argument from the list.

{ }

Braces are used with OR-bars and enclose a list of choices. You must choose one argument from the list.

...

Three dots (...) indicate that you can repeat the previous argument. If you use them with brackets, you can specify zero or more arguments. If they are used without brackets, you must specify at least one argument, but you can specify more.

The language requires many characters not included in the preceding list. You must enter required characters exactly as shown.

References

Text within brackets ([ ]) is a reference. See Appendix A, References of the Spectre Circuit Simulator Reference manual for more detailed information.

Kundert, Kenneth S. The Designer’s Guide to SPICE & Spectre. Boston: Kluwer Academic Publishers, 1995.
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