RE: XAUI Driver Spec
I See.
The question is: the 200mv signal at the receiver inputs is the size of the
eye pattern (mesured under standard jitter conditions), or the value does
not include jitter.
Boaz
> -----Original Message-----
> From: Ali Ghiasi [mailto:aghiasi@xxxxxxxxxxxxx]
> Sent: Monday, November 06, 2000 4:15 AM
> To: Boaz Shahar
> Cc: Robbie Shergill; stds-802-3-hssg@xxxxxxxx
> Subject: Re: XAUI Driver Spec
>
>
>
> Hi Boaz
>
> The 900 mV is due to signal attenuation as FR4 are predominately
> loss limited.
>
> Thanks,
>
> Ali
>
> Boaz Shahar wrote:
> >
> > Hello Ali,
> > I have a question in regards to your presentation for Tampa:
> >
> > You assert that the 900mv signal is attenuated to 200mv due
> to a loss of
> > 13db. This loss includes Jitter? That is, the height of the
> eye pattern in
> > the receiver's input is 200mv or less then that due to jitter?
> >
> > Thx.,
> > Boaz
> >
> > > -----Original Message-----
> > > From: Ali Ghiasi [mailto:aghiasi@xxxxxxxxxxxxx]
> > > Sent: Friday, November 03, 2000 6:17 PM
> > > To: Robbie Shergill
> > > Cc: stds-802-3-hssg@xxxxxxxx
> > > Subject: Re: XAUI Driver Spec
> > >
> > >
> > >
> > > HI
> > >
> > > The receiver max amplitude need to be higher than
> transmitter to allow
> > > some
> > > margin and protection. Very likely in Tampa the max transmit
> > > amplitude
> > > will
> > > be raised, where 1.6 V max will become more logical. The
> 1.6 volts is
> > > p-p
> > > diff. so each wire only drives 800 mV.
> > >
> > > Thanks,
> > >
> > > Ali
> > >
> > > Broadcom
> > >
> > > Robbie Shergill wrote:
> > > >
> > > > Hello all,
> > > >
> > > > Last week in Austin the XAUI group decided to change Max
> > > Diff. Amplitude to
> > > > 1.6 volts. As I understood it, the rationale for increasing
> > > the max amplitude
> > > > was to achieve commonality with the Infiniband spec.
> > > Although I agree with
> > > > the spirit of this rationale, I checked the Infiniband spec
> > > and found
> > > > that they are trying to drive a cable as well as a
> > > backplane with one
> > > > electrical specification; thus the reason for the 1.6v
> spec. In this
> > > > case, I'm not sure if it is worth matching the Infiniband
> > > spec in this
> > > > one area. My feeling is that a driver circuit can be
> made to drive
> > > > up to either 1.0 volt or 1.6 volt relatively easily;
> but it would be
> > > > much more troublesome for a (XAUI) receiver to tolerate
> 1.6 volts
> > > > *needlessley*.
> > > >
> > > > So, if the above reasoning is agreed to by others, I would
> > > propose that we
> > > > stay with 1.0 volt max. diff. amplitude that is in the
> > > current draft 1.0
> > > > (page 119, line 22).
> > > >
> > > > -Robbie Shergill
> > > > National Semiconductor
> > >
>