ModelSim SE User's Manual - Electrical and Computer Engineering

UM-98 4 - VHDL simulation
to_real()
ModelSim SE User’s Manual
to_real() converts the physical type time value into a real value with respect to the current
simulator resolution. The precision of the converted value is determined by the simulator
resolution. For example, if you were converting 1900 fs to a real and the simulator
resolution was ps, then the real value would be 2.0 (i.e., 2 ps).
Syntax
realval := to_real(timeval);
Returns
Name Type Description
realval real The time value represented as a real with
respect to the simulator resolution
Arguments
Name Type Description
timeval time The value of the physical type time
Related functions
get_resolution (UM-96)
to_time() (UM-99)
Example
If the simulator resolution is set to ps, and you enter the following function:
realval := to_real(12.99 ns);
then the value returned to realval would be 12990.0. If you wanted the returned value to be
in units of nanoseconds (ns) instead, you would use the get_resolution (UM-96) function to
recalculate the value:
realval := 1e+9 * (to_real(12.99 ns)) * get_resolution();
If you wanted the returned value to be in units of femtoseconds (fs), you would enter the
function this way:
realval := 1e+15 * (to_real(12.99 ns)) * get_resolution();