ModelSim SE User's Manual - Electrical and Computer Engineering

UM-542 B - ModelSim variables
Simulator state variables
ModelSim SE User’s Manual
Unlike other variables that must be explicitly set, simulator state variables return a value
relative to the current simulation. Simulator state variables can be useful in commands,
especially when used within ModelSim DO files (macros). The variables are referenced in
commands by prefixing the name with a dollar sign ($).
Variable Result
argc returns the total number of parameters passed to the current macro
architecture returns the name of the top-level architecture currently being
simulated; for an optimized Verilog module, returns architecture
name; for a configuration or non-optimized Verilog module, this
variable returns an empty string
configuration returns the name of the top-level configuration currently being
simulated; returns an empty string if no configuration
delta returns the number of the current simulator iteration
entity returns the name of the top-level VHDL entity or Verilog module
currently being simulated
library returns the library name for the current region
MacroNestingLevel returns the current depth of macro call nesting
n represents a macro parameter, where n can be an integer in the range
1-9
Now always returns the current simulation time with time units (e.g.,
110,000 ns) Note: will return a comma between thousands
now when time resolution is a unary unit (i.e., 1ns, 1ps, 1fs): returns the
current simulation time without time units (e.g., 100000)
when time resolution is a multiple of the unary unit (i.e., 10ns,
100ps, 10fs): returns the current simulation time with time units
(e.g. 110000 ns) Note: will not return comma between thousands
resolution returns the current simulation time resolution
Referencing simulator state variables
Variable values may be referenced in simulator commands by preceding the variable name
with a dollar sign ($). For example, to use the now and resolution variables in an echo
command type:
echo "The time is $now $resolution."
Depending on the current simulator state, this command could result in:
The time is 12390 ps 10ps.
If you do not want the dollar sign to denote a simulator variable, precede it with a "\". For
example, \$now will not be interpreted as the current simulator time.