I find it more natural to think of software as different internal states of hardware or driving the state changes, at least. For FPGAs, the "software" defines

I find it more natural to think of software as different internal states of hardware or driving the state changes, at least. For FPGAs, the "software" defines the hardware (in a sense) so there is a very tight integration between the two - to the extent that there really isn't any.