gEDA-user: FYI: new ethernet chip

[DJ Delorie <dj@xxxxxxxxxxx>]

Ran across this today, looking for alternate ethernet chips for my
furnace (boy, that doesn't get old... ethernet furnace... ethernet
furnace... ;)

http://www.silabs.com/tgwWebApp/public/web_content/products/Microcontrollers/Interface/en/CP220x.htm

This is a 48-TQFP (0.5mm pitch) chip with an 8 addr 8 data standard
"parallel" MPU interface on one side, and a simple twisted pair
interface (i.e. direct to an rj45 with integrated magnetics and LEDs)
on the other side.

There's a 28-QFN version with multiplexed bus if you need it to be
about 0.5cm square ;-)

The only drawbacks are that it's a 3.3v part (no 5v option), and
requires a 1:2.5 Tx transformer (less common than the 1:1).  In my
case, that translates into a different power supply (the m32c allows
for split power, whew) and - unfortunately - the magnetics are limited
to jacks that put the tab against the pcb, making it damn hard to get
the plug back out again.  I think I may be able to use non-integrated
magnetics and a tab-up jack, though.  Or I'll just put a big via under
the tab so I cak poke it from behind ;-)

Anyway, Mouser has these in stock for $4.42, plus an eval kit that
combines the chip, an 8051 clone, and a jack for $20.