Ah, my first NESdev question in four years :)

I was curious, are the writes in the standard write and r/m/w instructions the last cycle of the op? (except the write for the modify, obviously). I imagine the first bits are for reading the instruction/data/doing the addressing, then the modify write (when applicable) then the full-on write. Is this accurate? I'm just making stuff up here, so I'm not informed in the least.

I'm curious because I want to be super-accurate with PPU/sound register writes/reads. You know, because I can.

Thanks in advance,
Josh.