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I don't know if this has been discussed before on the conference calls but does anyone know why the sonet jitter mask (for the Rx) has 2 breakpoints. By breakpoint, I mean the points where the graph of jitter tolerance goes from being flat to sloping down at 20db/decade.For instance, for Oc48, you have breakpoints at 600Hz and 100k.
If you have a PLL, you should generally have only 1 breakpoint, given by the loop bandwidth. That I believe is followed in the FC/GBE communities.
Thanks
ps: Another thing, does anyone know the reason why the high frequency jitter tolerance in FC/GbE was reduced from the sonet .15UI to .1UI
-----Original Message-----
From: Anthony Sanders [mailto:anthony.sanders@infineon.com]
Sent: Tuesday, February 20, 2001 7:55 AM
To: Serial PMD reflector (E-mail)
Subject: XAUI Jitter Telco Protocol 14th Febuary 2001
Please find attached
1) Protocol from XAUI Jitter Telco, 14th Febuary 2001
2) Updated Jitter Issue List
Please pay attention to two important items, which I would like to get
feedback concerning these item on the reflector asap.
Section 2.5.4; Compliance Receive Eye. My proposal is that we shall not
define a compliance eye directly for receiver tolerance testing, but
only the necessity of including a filter (equal to the polynomial of the
compliance channel), to limit the edge speed.
Section 6.5.1; Use of CJPAT for compliance testing of receiever and
transmitter.
Does this requirement create too much restriction on the implementor
and testor?
Is this requirement necessary to guarentee interopability between
devices?
Is the current jitter specification correct, for CJPAT or K28.5
compliance testing.
Next telco, as always Wednesday, 10:30 (PST)
Best regards,
Anthony Sanders
Principal Engineer
Infineon Technologies
Munich, Germany