The Designer's Guide to VHDL, 2nd Edition

18 Files and Input/Output

In this chapter we look at the facilities in VHDL for file input and output. Files serve a number of purposes, one of which is to provide long-term data storage. In this context, “long-term” means beyond the lifetime of one simulation run. Files can be used to store data to be loaded into a model when it is run, or to store the results produced by a simulation. VHDL also provides specialized versions of file operations for working with text files. We show how textual input and output can be used to extend the user interface of a simulator with model-specific operations.

18.1 Files

We start our discussion of files by looking at the general-purpose mechanisms provided in VHDL for file input and output. VHDL provides ...