Re: [10GBASE-CX4] SIGNAL_DETECT
My $0.02,
I think Shawn has a good point here. The resultant receivers' sensitivity
could end up quite low and therefore random noise could trigure a
SIGNAL_DETECT. If we were to use the CL 48 state machine fault sections then
we presuppose there will always be a PMD and a PCS in the same Si.
Another way to look at the problem would be to look at what the amplitude
of the high frequency signal would be (the "1010...", the transition
..,0,1,...). Allowing for a loss of 16-20dB from transmit mdi to receive mdi
then we could specify if the receive signal goes above -20dB of the transmitted
signal SIGNAL_DETECT goes on and if it doesn't for 32ns after that it goes off.
Howard
"Rogers, Shawn" wrote:
> My $0.02:
>
> I do not see how SIGNAL_DETECT can be specified in terms of a receiver
> sensitivity threshold when, based on data presented, the receive eye will
> likely be completely closed.
>
> Even if not completely closed, there is a high likelihood that the receiver
> min threshold will be so low that, even after EQ, you will not be able to
> accurately apply a level test to determine whether there is adequate signal
> to make a decision.
>
> I believe the right approach lies in using the state machines provided in
> Clause 48 to declare a Local Fault condition.
>
> Shawn
>
> ____________________________________________
> Shawn Rogers, PMP s-rogers@ti.com
> High Speed Serial Link Marketing
> Texas Instruments
> 12500 TI Boulevard / M/S 8732/ Dallas, Texas 75243
> Office: 214.480.2678 Cell: 214.549.4868
> ______________________________________
>
>
> -----Original Message-----
> From: Petre Popescu [mailto:popescu@mail.quaketech.com]
> Sent: Monday, January 27, 2003 12:16 PM
> To: 10GBCX4
> Subject: [10GBASE-CX4] SIGNAL_DETECT
>
> Howard,
> Please find attached the text proposed for SIGNAL_DETECT.
> I found the most appropriate text for our applications in clause
> 39 (1000BASE-CX).
> Regards, Petre
>
> --
> Petre Popescu
> Quake Technologies
> 613.270.8113.x2229
> 613.220.8982 (cell)