[eepro100] Receive Buffer Descriptors

Naga R Narayanaswamy nraju@erols.com
Thu, 03 Aug 2000 07:11:52 -0400

Thanks Donald, I have a basic doubt remaining though.

>> 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.

>The first RFD points to all of the buffers.
>Using this model requires the chip to do extra PCI bus transactions,
and the
>driver has to do extra housekeeping.

My understanding is one RFD is used for one ethernet frame received.
(For the sake of easiness assume one buffer holds a complete
ethernet frame). So, in flexible model, if the first frame is received
in first RFD where do the subsequent frames go ?? If they go to the
next RFD's we do not have RBD's associated from them.

I have a chain of RFD's but I still do not get the point
why only first RFD point to the buffers (I may have only one
if the buffer is capable of holding a complete ethernet frame)
and the subsequent RFD's has no buffers.

I am coming from a 21143 world where, each rx descriptor
has a pointer to a buffer.

Fairfax, VA 22033