[eepro100] Receive Buffer Descriptors

Naga R Narayanaswamy nraju@erols.com
Wed, 02 Aug 2000 20:13:17 -0400

Hi Everyone,

In the context of the ongoing discussions regarding descriptors,
I have a question on the receive buffering scheme in the 82559
chip. It pertains to the simplified model and the flexible model
in the receive descriptors.

In simplified model the frame follows the descriptor immediately.
In the flexible model, the first RFD has a linked list of RBD's,
and subsequent RFD's have the RBD address set to NULL.
In other words only the first RFD can have RBDs.
Am I correct ? Any idea why is it like this? What if I descriptor
and frame not in contiguous memory and I want to make a
ring of descriptors?

Thanks in advance