XMODEL™ is an extension to your existing System Verilog simulator such as VCS, NC-Verilog, and Questa/ModelSim, enabling fast and accurate simulation of analog/mixed-signal systems with functional models and circuit-level models.
Since XMODEL™ can perform analog simulation entirely in SystemVerilog without involving SPICE, it is ideally suited for verifying large, complex mixed-signal systems where the mixture of digital and analog poses challenges to the existing tools such as SPICE, Verilog-AMS, and Real-Number Verilog.
XMODEL™ uses revolutionary, patent-pending algorithms to express analog waveforms in functional expressions and compute them efficiently in an event-driven fashion. As a result, the functional models composed with XMODEL™ primitives in SystemVerilog can achieve up to 10~100x speed-up over Verilog-AMS or Real-Number Verilog, which must compute all the values on the waveforms for accurate results.
XMODEL™ provides a rich set of primitives that let you build analog models and testbenches with. Just connect them up as building blocks; unlike Real-Number Verilog, virtually no programming is required. XMODEL™ primitives are extensive and parameterized; use them as basic operators to build your own component library!
In addition to the functional primitives, XMODEL™ also provides a set of circuit-level primitives such as resistors, capacitors, transistors, and even transmission lines. With these circuit-level primitives, one can easily compose models with various analog effects such as loading, nonlinearity, switching, and multiple drivers, which is not directly supported by Real-Number Verilog (a.k.a. wreal models). Yet, the simulation still runs entirely in SystemVerilog without invoking SPICE.
XMODEL™ has a unique capability of computing the signal’s statistical property during time-domain simulation, with significant speed-ups over the traditional Monte-Carlo simulations. For instance, it takes only about 10 seconds to estimate the bit-error rate (BER) of a high-speed wireline transceiver down to 10 -12.
When supported by your SystemVerilog simulator, XMODEL™ modules can interface with SPICE netlists as well as Verilog-AMS or Real-Number Verilog modules. With this co-simulation feature, you can verify your model’s equivalence with the circuit by comparing their respective responses to the same testbench and stimuli written in XMODEL™.
XMULAN is an extensive Python library included in the XMODEL™ package that allows you to streamline XMODEL™ simulations and post-process their results. With XMULAN, you can write Python scripts that perform simulations while sweeping parameters, collect results, and post-process them for display or recording.