ASIC miners hash quicker with less electricity draw over time due to microprocessor chip advancements, ie J/TH efficiency. ASIC are only designed to do the SHA-256 algo, whereas CPUs and GPUs can be reprogrammable. In general ASIC advancements follow Moore's law.
Mining pools use protocols such as Stratum to communicate.
However, I'd find it unusual to implement this in firmware or in an ASIC. I'd expect the ASICs to be dedicated to hashing and have pool communication handled by a supervisory computer. But I've not designed ASICs or mining systems so maybe my intuition here is weak.