ARCnet interface gate count

A *very rough* estimate would be to look at the size of a 10Base-2 Ethernet Phy + MAC. Sure, the implementation will be totally different, but the basic functions and speed are equivalent.

You may need a few k bytes of buffer ram, but this may be shared with your system ram if you're short of chip area.

IIRC, Arcnet drives a rather large signal (some V p-p) into a 93 ohm cable. You will probably need a heavy duty driver just to get the current. It may turn out to be more cost effective to use a separate chip for that. The last time I designed one of these, I used a fastish opamp (LM6061?) and an LH0002 to drive the cable. That was for a one-off, cost-insensitive project.

Regards, Allan

Allan Herriman a =E9crit:

Sounds good... :o)

I'm in the preliminary phase of the project (feasability study, actually). I get some inspiration from SMSC's COM20020 datasheet. This chip has 2Kbytes of RAM.

Still following SMSC's datasheet... Their evaluation board uses an HYC9088 as physical interface so I guess I'll use it too.

Thanks a lot Nicolas