Re: 16-bit 625Mbaud XGMII
Mittal
A couple of minor points on XAUI:
1) Speed: XAUI serial lanes are self-timed (i.e. no clock accompanies the data
in either direction) and operate at 3.125 Gbaud. Because of 8B/10B coding, the
highest frequency observed on PCB traces is 1.5625 GHz, not 3 GHz.
2) Pin Count: It's exactly 16. 4 in each of 2 data directions, differential.
Best Regards,
Rich
--
"Mittal, Millind" wrote:
>
> Curt, Jaime - But in this discussion, pin count is not the only
> consideration. Other important consideration is the length of the wire that
> you can drive. Isn't LVDS 16 bit interface is better than half speed single
> ended interface?
>
> Can someone refer me to some discussion where we have comparison of
> different options done in one place
>
> for example something like this ..
>
> XAUI LVDS singled ended
> speed 3 GHz 625 MHz 312 MHz
> pin count 20+ 70+ 70+
> distance drive ability 20" ?? 2"
> coding scheme requried yes no no
> design complexity
> etc...
>
> also did any proposal consider something in between 4 wide and 16 wide, for
> example 8 wide differential signaling interface?
>
> Millind Mittal
> Level One Communications/An Intel Company
> mmittal@level1.com
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