RE: [ethmac] About FlowControl and VLAN

["NewsGroup" <nbase@nbase.com>]

12-Oct-00

   Hi,

	I'm not sure if your question is from the Rx point of view or TX .

if the RX than the answer is simple as soon as you get the flow control
packet you read the timer field and "multiply" it in slot time and this is
the delay (obviusly it is not real multiply but rather shift or double
counter etc etc).

if the TX than the time you need to put if you don;t want to use ffff and
0000 (and I wonder why not ?) is the time it will take your RX path to free
it's input buffers

have a nice day

   Illan

-----Original Message-----
From: owner-ethmac@opencores.org [mailto:owner-ethmac@opencores.org]On
Behalf Of Mahmud Galela
Sent: Friday, October 06, 2000 8:37 PM
To: ethmac@opencores.org
Subject: RE: [ethmac] About FlowControl and VLAN




On Fri, 6 Oct 2000, NewsGroup wrote:

> 6-Oct-00
>
>    Hi,
>
> 	Just had a new machine and got some of the old email that was stored on
the
> server however some mail got lost so hope I don't say something that was
> already said.
>
>
> >-> FlowControl:
> >Well I found the corresponding information in the standard. I think it's
> nice to
> >have a FlowControl implemention on receiver side to disable the
> transmitter. But
> >what's about transmitter side - should there be any hardware support for
> sending
> >FlowControl frames?
>
> Just as you have in the reciver a simple counter that hold the transmiter,
> if your back side have no more space you should send a flow control to
stop
> the other side from keep sending data.
>
> the simplest and as far as I know most used technique is simple to send
> either flow control packet with timer equal ffff or timer equal 0000 so it
> work in sort of Xon/Xoff .
>
> This methode is not only the simplest to impliment but in most case will
> give just the same performance as sending a calculated timer.
>


>
> have a nice day
>
>    Illan
>


just want to know, how to determinate the time which is needed to pause
frame transmission that to be sent in flow control packet ?

regards,

mahmud