RE: SJTP: Minutes from today's call
Hi, Tim,
You are correct in that the jitter test pattern must not be allowed to propagate beyond the PHY layer in an ELTE. In jitter test mode, the WIS receiver is inoperative, and presumably the ELTE interface is disabled to avoid generating a large number of spurious errors.
About the provision of data at 9.95328 Gb/s from the PCS to the XSBI: I cannot presume to speak for all implementations, but I don't see any problem with accomplishing this. In the designs I have seen, the output of the PCS gearbox is clocked from the XSBI, so this would be quite easy to implement.
Cheers,
- Tom
-----Original Message-----
From: Tim Warland [mailto:twarland@xxxxxxxxxxxxxxxxxx]
Sent: Thursday, April 19, 2001 6:00 AM
To: serialpmd
Cc: Tom Alexander
Subject: Re: SJTP: Minutes from today's call
Tom Alexander wrote:
> Ben (and others),
> <snip>
>
> Further:
> - the WAN-PHY has a bypass mode specified, whereby the output of the 64B/66B PCS can be directly passed to the XSBI;
> - therefore, if a common test pattern can be created and specified in Clause 49, and allowed to be operative in both
> LAN-PHY and WAN-PHY (bypass) modes, no further changes to the spec are needed;
The WIS bypass allows the PCS connection directly to the PMA. However, if only 10GBASE-W
port types can be supported this bit is in-active. Therefore the proposed solution will
not work for all cases.
A possible work-around is to change the functionality associated with the bypass.
It should be possible to connect the PCS directly to a 10GBASE-W port type if
the data rate from the PCS was limited to 9.95328Gbps. Can the PCS support this
additional data rate for jitter test pattern generation?
Related to this, when jitter test pattern mode is used in a system operating
with a WIS and an ELTE, I am assuming that the ELTE would terminate
the jitter test pattern and not forward this to the far-end ethernet port.
Is this correct?
--
Tim Warland P.Eng.
Hardware Design Engineer Broadband Products
High Performance Optical Component Solutions
Nortel Networks (613)765-6634