Question: Why do some phy chips need FW?

AFAIK, some Marvel phy chips like AQR107(10G)/AQR108(5G) need FW. However, QCA phy chip qca8081(2.5G) doesn't need. I'm confused by this question. Why? Do some advanced features require FW? Does this mean there is a CPU/MCU in the phy chip which needs FW?

Yes, there is an MCU that runs the FW

Robert, do you know why qca8081 doesn't need FW? Thanks!

Because it doesnt have an MCU that supports that

OK,but I want to know why some Marvel chips need FW? What's the purpose? To support advanced features like what I guess? If yes,any more details?

Because they are designed like that in order to support all of the advanced features and their combinations, same goes for pretty much anything doing anything smart these days

Because Marvell designed it that way, sometimes it is that simple.

There is also the case where an MCU is there but installed from factory. No way to upgrade it and you keep all the bugs in it. Aquantia wanted to do things more modular by using more advanced chips for the PHY