[iron2disulfide]

The functionality of the F-91W is simple enough that I don't think a CPU would even be needed. Probably the digital parts of this chip are just state machines. That being said, the left half of the die shot looks like some kind of gigantic ROM, which could either be used by a CPU (as static program memory) or just transition logic/data for any generic state machine(s).

Verilog came out in 1984, but its use for synthesis (i.e. actually compiling text into circuits) was not popularized until much later, after correctness bugs in synthesizers and various other advancements in design tooling came around. It might have been used as a simulation/verification language for the digital portions of this chip.

[somat]

vhdl started as a project to document integrated circuits. The department of defense was getting a lot, and more complicated, integrated circuits and wanted a standard to document the functionality. At some point someone thought, "you know, if the documentation is good enough we could reverse it and synthesize a circuit from it", and thus why you use vhdl(or more likely verilog) to program your fpga.

The two languages fill the same role in the ecosystem, I have to say that I have never used ether, but my impression is that vhdl has clearer syntax(if you can stomach it's ada look and feel) and verilog has better tooling. which makes sense considering that one was a documentation project and the other was an internal tool for simulation that escaped into the wild.