Looking at what the PLA actually does, though, isn't it tantamount to a cleverly compressed microcode ROM? As far as I understand it, the opcode and cycle numbe

Looking at what the PLA actually does, though, isn't it tantamount to a cleverly compressed microcode ROM? As far as I understand it, the opcode and cycle number select a "word" of control signals to spit out, and the PLA aspect is primarily used to allow multiple permutations of cycle+instruction to select the same "microinstruction" without duplicating it as a conventional ROM would require. edit: I realize that in some trivial sense any combinational logic is tantamount to a compressed ROM, but I mean that even in a design sense this seems like it's not far off from a deduped array of microinstructions.