Re: [10GBASE-CX4] Cable / Connector pinout
Horie,
I concure with Pat to a degree. The thing we must keep in mind is that
we want to use what is available today without change as much as
possible. All we are doing is putting the appropriate specifications in
place to existing technology to ensure the system will work and product
will interoperate. Besides the IB pinout is the better pinout, the same
device can be used on either side of the link with the exact same layout
while the Xenpak pinout forces a cross over on one of the sides.
Howard Baumer
pat_thaler@agilent.com wrote:
>
> Horie,
>
> The pin out reflects the way the wires run in the cable. For Infiniband cable, the cable includes a "crossover" so that both ends have the same connector pin out. For example, S1 on one end of the cable is wired to S16 on the other end so that one ends RX0+ connects to the other ends TX0+.
>
> If one uses the pinout you suggest, the two ends of the cable have to have different signal assignments (as in Ethernet 10BASE-T MDI and MDI-X connector pin definitions). For 10BASE-T, this wasn't a big deal as there are only four pins so it is pretty easy to swap pins where needed with an MDI/MDI-X switch. For 16 bits and 3+ GigaBaud signal rate, this isn't convenient and one should stick to having both ends use the same pinout.
>
> Pat
>
> -----Original Message-----
> From: Takeshi Horie [mailto:horie@fla.fujitsu.com]
> Sent: Tuesday, December 10, 2002 12:31 PM
> To: 10GBASE-CX4 (E-mail)
> Subject: RE: [10GBASE-CX4] Cable / Connector pinout
>
> Dan,
>
> I thought we dont have to follow IB pinout definition, although IB cable
> is used. Do I miss something?
>
> Better way is to have pinout order consistent with XENPAK so that one
> SERDES chip can be connected to CX4 and XENPAK only with minor trance
> change.
>
> How about the following pin assignment?
>
> IB 4X connector
> ------------------------
> IB Pin Signal
> ------------------------
> S16 TX3-
> S15 TX3+
> S14 TX2-
> S13 TX2+
> S12 TX1-
> S11 TX1+
> S10 TX0-
> S9 TX0+
> S8 RX3-
> S7 RX3+
> S6 RX2-
> S5 RX2+
> S4 RX1-
> S3 RX1+
> S2 RX0-
> S1 RX0+
> ------------------------
>
> TX*=IBtxO*
> RX*=IBtxI
>
> Thanks,
>
> - Horie, Fujitsu Laboratories of America
>
> > -----Original Message-----
> > From: owner-stds-802-3-10gbcx4@majordomo.ieee.org
> > [mailto:owner-stds-802-3-10gbcx4@majordomo.ieee.org]On Behalf
> > Of Howard A. Baumer
> > Sent: Tuesday, December 10, 2002 10:11 AM
> > To: 10GBASE-CX4 (E-mail)
> > Subject: Re: [10GBASE-CX4] Cable / Connector pinout
> >
> >
> >
> > Dan,
> > I have Vol 1, Rev 1a and Vol 2, Rev 1. I didn't have
> > Vol2, Rev 1a.
> > After looking at Vol 2, Rev 1a all is fine and the cables match the
> > spec.
> >
> > Thanks,
> > Howard
> >
> >
> > "DOVE,DANIEL J (HP-Roseville,ex1)" wrote:
> > >
> > > Hi Howard,
> > >
> > > I am looking at the spec and find that the
> > > cable signals are consistent with my draft
> > > and your stated IB Signal is different.
> > >
> > > The document I hold, Volume2 rev 1.0a has
> > > change bars on those signals as if they were
> > > the most recent change.
> > >
> > > This suggests you *may* be looking at an old
> > > draft. (please oh please oh please!!)
> > >
> > > Can someone more familiar with this matter
> > > please reply to this?
> > >
> > > Thanks,
> > >
> > > Dan
> > >
> > > -----Original Message-----
> > > From: Howard A. Baumer [mailto:hbaumer@broadcom.com]
> > > Sent: Tuesday, December 10, 2002 8:44 AM
> > > To: 10GBASE-CX4 (E-mail)
> > > Subject: [10GBASE-CX4] Cable / Connector pinout
> > >
> > > All,
> > > I just noticed that the connections for the Cable
> > assemblies we have
> > > been dealing with do not match the connections in the IB
> > specification.
> > > Here is what I have determined:
> > > IB IB Cable
> > > Pin Signal Signal Difference
> > > S1 IBtxIp(3) IBtxIp(0) X
> > > S2 IBtxIn(3) IBtxIn(0) X
> > > S3 IBtxIp(2) IBtxIp(1) X
> > > S4 IBtxIn(2) IBtxIn(1) X
> > > S5 IBtxIp(1) IBtxIp(2) X
> > > S6 IBtxIn(1) IBtxIn(2) X
> > > S7 IBtxIp(0) IBtxIp(3) X
> > > S8 IBtxIn(0) IBtxIn(3) X
> > > S9 IBtxOn(3) IBtxOn(3)
> > > S10 IBtxOp(3) IBtxOp(3)
> > > S11 IBtxOn(2) IBtxOn(2)
> > > S12 IBtxOp(2) IBtxOp(2)
> > > S13 IBtxOn(1) IBtxOn(1)
> > > S14 IBtxOp(1) IBtxOp(1)
> > > S15 IBtxOn(0) IBtxOn(0)
> > > S16 IBtxOp(0) IBtxOp(0)
> > >
> > > The Cables IBtxI lane order is reversed from the IB
> > Specification. I am
> > > looking at "InfiniBand Architecture Release 1.0 Volume 2 - Physical
> > > Specifications" page 160 & 161, table 24.
> > >
> > > Howard Baumer
> >
> >