Simulation Overview
While a good design naturally follows from
quality schematics, truly great designs can made with the help of
simulation. Multisim provides powerful simulation capabilities and
features which are simply unavailable in other EDA packages.
Simulating a design can result in fewer design
iterations and less chance of errors in the prototype stage of
product development. When a design is simulated at the front end of
the design process, the number of design cycles can be
significantly reduced.
In addition to a world-class SPICE simulator,
Multisim also includes XSPICE simulation, enabling fast simulation
of digital other components.
Patented co-simulation techniques allow
designers to simulate VHDL modeled components along with the rest
of a circuit. With MultiMCU, certain microcontrollers can be
simulated in the very same mixed-mode environment. MultiMCU is not
available for all versions of Multisim.
Using the Interactive Simulator
To begin a simulation, ensure that the circuit
has all the necessary prerequisites. All circuits must include a
ground reference, and a source. Once the circuit is ready for
simulation, click the Run / Stop Simulation button
or press F5. An interactive circuit simulation will
begin.
The settings that are used for interactive
simulation can be viewed and modified by selecting
Simulate/Interactive Simulation Settings.Figure 1 below illustrates
some of the settings available for interactive simulation. The
default end time for the simulation is 1e+30 seconds, or around
3.17e+30 billion years. By default time steps will be generated
automatically.
To view results of this simulation, the
measurement probe
can be used dynamically. Simply click on the probe icon
and the mouse cursor will turn into a probe. The mouse can then be
moved over any net to view the following metrics:
- Voltage (instantaneous, peak-to-peak, RMS, and DC).
- Frequency.
Virtual instruments can also display
simulation results. Virtual instruments are covered later in this
section.
Multisim also provides more traditional SPICE
analyses, which are run through the Grapher/Analyses List toolbar
button,
or by selecting Simulate/Analyses. Analyses are
described in greater detail later in this section.
Handling Simulation Errors
Sooner or later, even the most experienced
SPICE users will run into a SPICE simulation error. Multisim
includes a simulation advisor to help discover and fix the source
of troubling errors.
When an error message appears such as the one
in Figure 5, click the Adviser button to access the available
help.
Two of the most often encountered errors are
timestep errors, and singular matrix errors. below provides the
most common solutions to these simulation errors.
"This course introduces National Instruments Multisim through instructional modules and hands-on exercises. Multisim is an interactive, graphical schematic capture tool and SPICE simulator that […]"