and it's likely that this is one of them. Once PAL's became popular, a number of devices like this one, and, in fact, a lot of "family logic" gradually fell into disuse. Even the PAL's have pretty well gone away now, and what one sees is a big chip, often with the MCU built into it, right along with those special functions. Using the special function IC's seldom had the sorts of side-effects occasionally encountered when building the big FPGA, though.

What it takes to keep manufacturers producing such devices is volume, and, with the advent of large field-programmable logic devices, the functions disappeared into them, rather than remaining obvious on the PCB. I miss a few of them, myself.

RE