thomas@uplog.se (Thomas Hameenaho) (11/15/88)
We are about to start the design of a fast VME based Ethernet board
(who aren't?), now I wonder what experience people have with the different
Ethernet controllers.
The chips we've been considering is the AMD 7990, i80586 and the Seeq 8003.
Any useable one missed?
The board will have a 68020 and 32 bit wide memory and will be optimized
for speed.
7990:
Advantages:
Builtin DMA.
Can handle the byte-sex of a 68K.
Fast, can according to AMD use down to 4.1 usec interpacket gap time.
Lots of implementations using it.
Disadvantages:
In-flexible DMA.
Lousy bus timing, must be isolated from the processor bus.
16 bits interface.
i80586:
Advantages:
?
Disadvantages:
Slow (rumors)
Wrong byte-sex.
8003:
Advantages:
No built in DMA. Allows flexible external solutions tailored
to mbuf like strategies.
No byte-sex problems.
Reasonable bus timing.
Simple.
Disadvantages:
Not very used.
No time-domain-reflectometer
Simple.
Please E-mail responses to me. I'll summarize if there's any interest
--
Real life: Thomas Hameenaho Email: thomas@uplog.{se,uucp}
Snail mail: TeleLOGIC Uppsala AB Phone: +46 18 189406
Box 1218 Fax: +46 18 132039
S - 751 42 Uppsala, Sweden