At the 2010 DACI moderated a panel session on SPICE and Fast SPICE circuit simulation, and one of the panelists was PierLuigi Dagliofrom STMicroelectronics. To get an update on SPICE circuit simulation at ST I read a PDF document at Mentor titled: Improving the Quality of SPICE Simulation Results with Eldo Premier at ST.
ST does IC design for many end-markets, like: Home, auto, health industry and mobile devices. Their AMS IC design flow covers a wide range of tools from Matlab at the system definition stage, down to SPICE at the IC implementation stage:
The CAD group has used the Eldocircuit simulator for many years, then decided to evaluate Eldo Premier, a Faster SPICE tool to see how it compared to Eldo Classic. A list of nine test cases was assembled that were simulated in transient analysis, transient noise analysis, and with language-based designs using the Questa ADMS simulator:
For these nine test cases the measured accuracy of Eldo Premier results versus Eldo Classic was within 1%, so the new simulator accuracy was acceptable.
A comparison of speed improvements show that Eldo Premier could deliver simulation results up to 5X faster than Eldo Classic. Here’s a chart comparing simulation speed across six CMOS test cases:
Modern SPICE simulators need to run on multiple CPUs in order to reduce the overal run times, and using up to 8 CPUs showed good speed improvements.
ST continues to use both Eldo Classic and Eldo Premier for transistor-level circuit simulations, depending on the design size. For netlists with more then 10K devices, they opt to use Eldo Premier. Simulation speed improvements when using language and transistors together also shows speed improvements up to 6X:
ST uses both Eldo Classic and the newer Eldo Premier in their circuit simulations, along with Questa ADMS. The transition from Eldo Classic to Premier was simple because there is no change required on the netlist, the accuracy is the same, and the results come back quicker. With more speed they can do bigger Monte-Carlo simulations that were impractical before.