– Copied from customer email –
I am using the Giga Nano and my application only needs 10/100MB ethernet . Should I use 75ohm resistors
to gnd for the unused two pairs of signals on each port?
No data will ever be sent on them for 10/100 so you can leave them unconnected. Some integration guides for connecting GigaBlox Nano to other 10/100 hardware can be found in the link below.