Spectre 26.1 Release Now Available

Hardware Acceleration

Spectre Job Manager

The new Spectre Job Manager (spectre_jm) enables multiple simulations to run in parallel on the same GPU, providing improved simulation throughput. Voltage-based asserts in transient analysis are now evaluated on the GPU, extending GPU support for device-checking asserts.

Core Spectre

Spectre X Runtime Estimation

Spectre X introduces post-simulation multi-core runtime estimates. For a simulation run with a given number of threads, this capability estimates the runtime that would be achieved with different thread counts, providing insight into simulation scaling behavior.

Process-Based Save Restart (PBSR)

Process-Based Save Restart (PBSR) provides a save-and-restart capability based on a complete snapshot of the simulation database. When restarting a simulation, selected simulation options and netlist parameters can be modified while preserving simulation state.

Thermal Node Support for DC Analysis

The thermal-node (tempnode) technology now supports DC analysis in addition to the analyses already supported, extending the range of analyses that can incorporate thermal modeling.

Spectre Viewer

Spectre Viewer is a graphical user interface tool for viewing simulation notes, warnings, and errors reported in the Spectre log file. It also supports viewing asserts and design-check SQL databases.

Spectre RF

Harmonic Balance (HB) analysis now supports fractional-divider circuits.

Regular Envelope analysis now supports multiple wsource definitions and multiple frequencies, enabling more flexible multi-source and multi-frequency simulations.

Solutions and Flows

Spectre FMC

Smart Corners analysis enables identification of worst-case samples across multiple process, voltage, and temperature (PVT) corners with significantly fewer simulations than running Monte Carlo analysis at every corner.

Smart Corners provides two analysis flows:

• Quick Screening Flow, which identifies worst samples only for the corners predicted to be most critical, reducing the number of simulations and improving runtime efficiency.
• Comprehensive Flow, which reports worst samples across all corners and verifies results across the entire corner space for greater analysis coverage.

FMC also supports transferring model-learning data from a previous FMC run and reusing it in a subsequent FMC run. This enhancement reduces the number of simulations required for the new FMC run by approximately 10–20%. In addition, FMC now supports combined FMC and 1+N Aging analysis.

Spectre EM-IR and Voltus-XFi Enhancements

A full current-based solver method is now available with the iterated analysis method. When used with a fixed second-stage timestep, it provides a high-performance solution for analyses that can tolerate lower accuracy.

Additional enhancements include:

• Support for designs that combine W-based and NFIN-based device definitions.
• What-If Analysis support for scaling MOSFET power-gate and tap devices.
• Support for modifying the DSPF RC network used during second-stage EM-IR analysis.
• Early power-gate connection reporting to identify detected power gates before running a full EM-IR analysis.
• Control over pin shorting during DSPF processing by using the shortPins option.

Legato Reliability Solution

Advanced Aging Reliability Analysis

Time-Dependent Dielectric Breakdown (TDDB) is now supported in the TMI, URI, and AgeMOS reliability analysis flows. Custom TDDB models can be implemented in the URI flow, enabling foundries and design teams to incorporate proprietary TDDB methodologies into reliability analyses.

Legato Fault Analysis

Legato Fault Analysis now supports the Effective Sample Size (ESS) method for weighted random fault sampling. ESS provides coverage estimation for weighted sampling flows.

The solution also identifies undetectable faults based on circuit activity and automatically excludes them from fault analysis. Output-weighted coverage diagnostic reporting is now available in both spectre_ddmrpt and spectre_fsrpt.

Legato Electrothermal Analysis

Legato Electrothermal Analysis now supports:

• Combined thermal modeling using ICT files for layer information, thproc files for material information, and CMX files for thermal parameter information.
• Wirebond thermal modeling.
• Multi-chip thermal modeling.
• Combined Electrothermal and EM-IR analysis, enabling evaluation of electrical and thermal effects within a unified analysis flow.

Legato Radiation Analysis

Legato Radiation Analysis is introduced in this release. It enables evaluation of radiation effects on integrated circuit designs used in radiation-sensitive environments, including aerospace and space applications.

The solution supports both:

• Single Event Effects (SEE) analysis
• Total Ionizing Dose (TID) analysis

Allowing assessment of transient and cumulative radiation-induced effects on circuit behavior.