Want to simulate logic gates

[usao]

I am a home hobbyist who builds small digital circuits for fun. I am
interested in designing a bigger project, probably a few hundred chips
of the 74HC family. I recently heard of VHDL, and wondered how I might
try this out.
Basically, I would like to create a program which would allow me to
watch the signal levels and single step the signals through gates to
look at timing and other stuff.
Im trying to locate a VHDL compiler (since it doesn't appear that GCC
on Linux supports *.vhdl files). I want to be able to compile it, and
step through it, making changes and watching it as I go.
Is this possible? Where is a freeware/gnu compiler? Does anyone know
if there is a GUI to observe the signals or do I need to gnuplot the
signal history?
Ron

 

[Allan Herriman]

On 13 Apr 2004 14:56:25 -0700, ron@argus.lpl.arizona.edu (usao) wrote:

I am a home hobbyist who builds small digital circuits for fun. I am
interested in designing a bigger project, probably a few hundred chips
of the 74HC family.

You might find it easier to use a single, cheap FPGA rather than
design something of this size out of SSI or MSI parts.

Evaluation kits are available; you won't even need to design a board.

I recently heard of VHDL, and wondered how I might
try this out.
Basically, I would like to create a program which would allow me to
watch the signal levels and single step the signals through gates to
look at timing and other stuff.
Im trying to locate a VHDL compiler (since it doesn't appear that GCC
on Linux supports *.vhdl files).

GCC is designed for compiling programming languages, and isn't really
suited to HDL (hardware description languages).

I want to be able to compile it, and
step through it, making changes and watching it as I go.
Is this possible?

This is possible, and done frequently!

Where is a freeware/gnu compiler? Does anyone know
if there is a GUI to observe the signals or do I need to gnuplot the
signal history?

If you drop the requirement for open source, there are a number of
free or low cost VHDL simulators of excellent quality, e.g. Modelsim
AE or XE, or Simili (http://www.symphonyeda.com/) Typically they have
a "free" license that is crippled in some way, usually simulation
speed, but that probably won't bother you (at first).

They come with waveform viewers ("GUI") built in.

Regards,
Allan.