Ethernet controller vs. Ethernet transceiver

Hey guys,


I found there are some kind microcontrollers building in Ethernet controller(like DS80C400). But the demo board still uses an extra etherenet transceiver.
So what is the difference between ethernet controller and ethernet transceiver?
I was using microprocessor + ethernet controller (RTL8019). If microcontroller has ethernet controller building in, why should I still have to use ethernet transceiver?


Thanks guys

ED

I may be wrong

Think of this in terms of a telephone system.

The tranceiver would be the phone at your house allowing you to speak and to hear (tranceiver=transmitter and receiver) and the controller would be telling the system where to call when you dial the number.

The tranceiver converts the various logic levels so that the signal can be sent or received down the line and the controller is the thing that figures out what is supposed to go where.

I think that's how it goes....

Resc.