On Sun, 2014-01-12 at 01:15 -0500, Adam Jensen wrote: > On Sun, 12 Jan 2014 05:03:13 +0100 (CET) > [email protected] wrote: > > > > If the generated binaries do inherit the GNU license, could the > > > author(s) be persuaded to change the license slightly? > > > > > > pragma License (Modified_GPL); > > > > I need good arguments. Is there any need to distribute generated > > binaries ? > > > > VHDL can be used for much more than just hardware description. Through > the foreign function interface, much additional sophistication can be > linked into the discrete-event core. Complex application software can > be created. It's just another programming paradigm.
There's a problem with this, as frequently pointed out by David Koontz : other languages don't share the discrete-event model. Thus the VHPI only really works in one direction : outwards from VHDL. That means you can call external functions from VHDL which will (from VHDL's POV) return within the same delta cycle, allowing VHDL to control the timing model. This mode of operation can be completely successful, as long as you can design the interactions around that constraint (which implies the calling process - and thus the entire sim time model) is blocked until the external function returns) Calling VHDL from external code, all I have managed to do is to run a top level design (which can then call back and dictate timings to external code). Now those external subprograms (called from VHDL, returning immediately) may control parallel software activities such as a GUI. But to do so they must be something like critical sections - an obvious model would be accessor methods to an Ada protected object. Thus for example if you're selling a UART chip, (but don't want it copied) you might provide a VHDL model callable from a software component representing the UART driver : that component would start the UART testbench and interact with it via protected objects representing the UART ports, and interact with the user app via the UART driver calls. In which case you might want to supply the VHDL component (testbench and UART, or possibly just the UART itself) as a binary. Too far fetched? - Brian _______________________________________________ Ghdl-discuss mailing list [email protected] https://mail.gna.org/listinfo/ghdl-discuss
