Technical data
virtual function
CR-184 ModelSim Commands ModelSim EE/SE Command Reference
virtual function
The virtual function command creates a new signal, known only by the GUI (not
the kernel), that consists of logical operations on existing signals and simulation
time, as described in <expressionString>. It can handle bit selects and slices of
Verilog registers.
The virtual function will show up in the wave and signals window as an
expandible object if it references more than a single scalar signal. The children
correspond to the inputs of the virtual function. This allows the virtual function to
be "expanded" in the wave window to see the values of each of the input
waveforms, which could be useful when using virtual functions to compare two
signal values.
Virtual functions can be used to gate the list window display.
Syntax
virtual function
[-env <path>] [-install <path>] [-implicit] {<expressionString>}
<name>
Arguments
(Arguments for virtual function are the same as those for virtual signal except
for the contents of the expression string.)
-env <path>
Specifies a hierarchical context for the signal names in <expressionString> so
they don’t all have to be full paths. Optional.
-install <path>
Causes the newly-created signal to become a child of the specified region. If -
install is not specified, the newly-created signal becomes a child of the nearest
common ancestor of all objects appearing in <expressionString>. If the
expression references more than one logfile (dataset), the virtual signal will
automatically be placed in region virtuals:/Signals. Optional.
-implicit
Used internally to create virtuals that are automatically saved with the List or
Wave format. Optional.
<expressionString>
A text string expression in the MTI GUI expression format. Required. See (TBD)
for a full and updated description.