A model of computation (MoC) is a set of rules defining the behavior and interaction between SystemC AMS primitive modules.
In the timed data flow (TDF) model, components exchange analogue values with each other on a periodic basis at a chosen sampling rate, such as every 10 microseconds.
A TDF model defines a method called `processing()' that is invoked at the appropriate rate as simulation time advances.
The periodic behaviour of TDF allows it to operate independently of the main SystemC event-driven kernel used for digital logic.
Current flowing in ELN networks of resistors can be solved with a suitable simultaneous equation solver.
For instance, to simulate the capacitor charge problem on the left below, a timestep delta\_t is selected that is typically about one percent of the time constant and the iteration on the bottom right is executed.
But this is not a problem in many situations where part of a complex SoC or plant controller is run alongside a plant model that has just a few state variables, such as the car transmission system because there are orders of magnitude difference in time constants (e.g. 100 MHz clock versus 1~ms shortest inertial time constant).
Under the ELN formalism, the SystemC initialisation and simulation cycles are extended to support solving nodal flow equations.
Iterative methods tend to have greater stability and are fast when the state has only advanced slightly from the previous time step.
The study group has made initial investigations and specified and implemented a SystemC extension to demonstrate feasibility of the approach.
[2][3] COSEDA Technologies provides with COSIDE the first commercially available design environment based on SystemC AMS standard.