Analogue behavioural modelling and simulation using VHDL and Saber-MAST

The IEEE standard 1076 VHDL (VHSIC Hardware Description Language) has been widely used as the universal medium for the exchange of designs and the simulation tool. The current version of VHDL is primarily used for digital simulations; it is not yet a mixed-mode simulator. However, it provides the capabilities of modelling analogue signals and analogue behavioural functions in addition to digital modelling. When modelling circuits behaviourally using VHDL, a suitable concurrent statement is the process statement. With the process statement, VHDL provides the facilities of a general-purpose programming language to the hardware designer. The Saber simulator (from Analogy) was initially an analogue simulator, but now it is a comprehensive mixed-mode simulator, spanning the analogue and digital domains. The Saber simulator provides a versatile modelling language called MAST which allows for easy addition of new models. Unlike SPICE, modelling can be done only at the netlist level and by using built-in models. Saber is a general-purpose simulator and can be used in a broad scope of applications. It can be applied to electrical, optical, thermal or mechanical systems or any combination of these different technologies as long as the model can be expressed in the form of algebraic and differential equations using MAST