ModelSim SE User's Manual - Electrical and Computer Engineering

UM-92 4 - VHDL simulation
Using alternative input/output files
Flushing the TEXTIO buffer
Providing stimulus
ModelSim SE User’s Manual
You can use the TextIO package to read and write to your own files. To do this, just declare
an input or output file of type TEXT. For example, for an input file:
The VHDL’87 declaration is:
file myinput : TEXT is in "pathname.dat";
The VHDL’93 declaration is:
file myinput : TEXT open read_mode is "pathname.dat";
Then include the identifier for this file ("myinput" in this example) in the READLINE or
WRITELINE procedure call.
Flushing of the TEXTIO buffer is controlled by the UnbufferedOutput (UM-534) variable in
the modelsim.ini file.
You can stimulate and test a design by reading vectors from a file, using them to drive
values onto signals, and testing the results. A VHDL test bench has been included with the
ModelSim install files as an example. Check for this file:
/modeltech/examples/stimulus.vhd