Re: gEDA: [cf-user] FNF: Netlist format for Confluence and Informal

[Tom Hawkins <tom-at-NOSPAMconfluent_dot_org>]

Stephen Williams wrote:
> Tom Hawkins wrote:
> | I started to define the format for FNF: the future netlist format of
> | Confluence and InFormal.
> |
> | FNF is a flat netlist that retains hierarchical scoping.  The netlist is
> | a directed graph of primitive RTL operations, called cells. Some basics:
> |   - All cells have 0 or 1 outputs.
> |   - All cells operate on bit vectors.
> |
> | The syntax definition is located here:
> |
> |   http://www.confluent.org/wiki/doku.php?id=fnf:main
> |
> | (Steve, hopefully this aligns with Icarus synthesis, when you move it
> | from bits to vectors.)
> 
> It does indeed appear to jive well enough. You will eventually be
> a need for data type declarations, as I expect nets to eventually
> be typed.

Hopefully nothing more complex than signed/unsigned.  Actually, why not 
convert all signed operations to unsigned ops for the internals?  This 
would make the primitive set a bit smaller -- my approach with Confluence.

> 
> | Shortly I will release an FNF generator for Icarus, followed by a
> | Verilog, VHDL, C, and NuSMV writer.
> 
> I think a generator for 0.8 will not be wasted, even though the 0.9
> branch is changing the ivl_target API. The concepts will be similar
> enough. What I see in the FNF page you have so far is compatible
> with both.
> 
> This really starts to get interesting when there are translaters from
> FNF to vvp. I'm starting to imagine mixed language Verilog/schematics
> simulation, post synthesis simulation, et al.

Yes.  I would prefer if Confluence users simulate with Icarus, rather 
than having to maintain a redundant C model generator.  Then they could 
take advantage of full VCD visability (currently lacking in CF).

Any plans for C model extraction with Icarus 0.9?

-Tom

> --
> Steve Williams                "The woods are lovely, dark and deep.
> steve at icarus.com           But I have promises to keep,
> http://www.icarus.com         and lines to code before I sleep,
> http://www.picturel.com       And lines to code before I sleep."