Spectre Tech Tips is a blog series aimed at exploring the capabilities and potential of Spectre®. You may also contact your Cadence support AE for guidance.įor more information on Cadence products and services, visit About Spectre Tech Tips Spectre ISR What's New release presentations on the Spectre product web page.Spectre Classic Simulator, Spectre APS, Spectre X, and Spectre XPS User Guide.
In one of the upcoming blogs, we'll discuss the Spectre X-RF distributed harmonic balance technology. In this blog, we introduced Spectre X-RF and observed the performance and memory consumption improvements it provides compared to Spectre APS RF. The following figure illustrates the memory reduction for the same representative post-layout designs. Spectre X significantly reduces the memory consumption for such designs. One challenge for the RF simulation of large, post-layout advanced node designs is the high memory consumption. If the RF simulation finishes in seconds to minutes, there may not be any performance gain from Spectre X because the time isn’t spent in RF analysis but rather in pre- and postprocessing. Note that a performance gain from Spectre X-RF can only be observed on a simulation-intensive RF analysis. It therefore provides best performance on the PSS shooting and the TSTAB simulation portion, while the gain in other large and small-signal RF analyses may be less. Spectre X-RF may also provide performance gains for other designs, but the smaller a design is, the more pre-layout character it has and the more legacy technology it uses, the less performance gain will be observed.Įxperience shows that Spectre X provides most performance gains on transient-like simulations. In conclusion, Spectre X provides a performance gain in RF analyses, however, the performance gain is typically less compared to a Spectre X transient simulation of the same design. The Spectre X-RF accuracy was confirmed to match the Spectre APS RF accuracy. A few of these designs used the shooting newton method, while others used the harmonic balance analysis method. The following figure shows the performance gains for a few representative, large, post-layout advanced node designs. The average Spectre X-RF performance gain over Spectre APS is around 2-3x for these designs. Spectre X-RF: Single Option Speed/Accuracy TradeoffĪs known from non-RF applications, the Spectre X engine provides the most performance gains for large, post-layout advanced node designs. The +preset use model applies to both Spectre X-RF shooting newton and harmonic balance methods. LX and VX are usually considered as too aggressive settings for RF analysis. Spectre X-RF is based on the same and simple usage model as Spectre with the addition of only the +preset values CX, AX, and MX.
Starting with SPECTRE 20.1, the Spectre X engine is also available in Spectre RF analyses, where it provides improved RF analyses performance and capacity compared to Spectre APS. It has already proven itself for non-RF applications at many customer tapeouts. The Spectre X engine was released in SPECTRE 19.1. The distributed harmonic balance (HB) analysis will be discussed in later blogs. In this blog, we'll focus on the single-machine multi-core Spectre X-RF simulation. Highly distributed multi-machine multi-core HB simulations ( +xdp mode).Single-machine multi-core Spectre X-RF simulations ( +preset mode).It includes the following two technologies: Spectre X-RF targets the most challenging RF simulation problems, including advanced node designs with complex FinFET (and other) device models and challenging RC-dominated post-layout designs. In this blog, we introduce the Spectre X-RF technology. The Spectre X-RF technology integrates the Spectre X engine into the RF analyses of Spectre.
We released Spectre ® X-RF in the SPECTRE 20.1 base release at the end of September 2020.