Thread Links Date Links
Thread Prev Thread Next Thread Index Date Prev Date Next Date Index

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@xxxxxxxxxx
                                 
------------------------------------------------------- 
Richard Taborek Sr.                 Phone: 408-845-6102       
Chief Technology Officer             Cell: 408-832-3957
nSerial Corporation                   Fax: 408-845-6114
2500-5 Augustine Dr.        mailto:rtaborek@xxxxxxxxxxx
Santa Clara, CA 95054            http://www.nSerial.com