Re: [ethmac] Remarks/Questions about the new Rx/Tx diagrams

[nbase <nbase@nbase.com>]

Hi,


>> Tx Machine :
>
>> 2. there is many generator block which I wonder what you need them for ? ,
>> for example jam , preambale , pad , I would think a simple 5 and D for
>> preamble and maybe 0 for jam and padding and than the tx machine contor the
>> mux which to use.
>
>I still wonder what you meant. I guess you want there is only one
>generator for jam, preamble, and pad. Is it right ?

No, the point is that there should be no generator at all this is simple a
pre-define number and so no need for any generator (in contrast to places
where a generator is needed like the random number generator)


>> 3. I wonder also what is this 8 bit of pause you pass from the Rx to the Tx
>> I would think a 1 bit signla of stop/start is enough ?
>
>Ehm... we plan flow control will recognize pause frame from Rx, and then
>give generate pause frame before Tx buffer and the information for Tx 
>machine.

well once the Rx "see" pause command and this of course mean full duplex
mode than the same machine can hold the value and count back and just pass
one start/stop signal to the Tx, but you can also put the counter in the TX
this is implemintation issue only.
keep in mind that to save some place you can use the same store FF for
counting down as the protocol say that a new flow will override the old so
you don't need to duplicate the FF's.

Oh one more thing you might want to do is start define also a test bench as
it is also not a small task and as such should start with defineition.

have a nice day

   Illan