Lower-volume specialty chips for interfaces (lots of I/O pins), such as adapters for an odd interface, custom hardware designs for which there isn't an existing

Lower-volume specialty chips for interfaces (lots of I/O pins), such as adapters for an odd interface, custom hardware designs for which there isn't an existing chip, etc. For instance, audio, video or other signal processing can be done by putting the algorithm "directly" into the hardware design; it will run at a constant predictable speed thereafter.