Written by Tom on Monday 04/06/07
ROM is used to store predetermined values. This might be some boot code for a VHDL micro implementation, or maybe a set of tap weights for a FIR filter.
Since it is read-only memory clock and write enable signals are not necessary. The circuit contains pre-stored words, these are selected via the address input (addr) and presented at the output (data).
From GTKWaveSignals.JPG the results of the simulation can be seen.
Download the project from here.
Use the go.bat to compile and run GTKWave.
I do not claim any originality in this article.
"Circuit Design with VHDL" by Volnei A. Pedroni.