Alvin & all,

This is to point out the pattern FC developed for the “spectrally flat” requirement.  The pattern described in the link below (authored by Tom Lindsay) is reasonably spectrally flat within the limits of 8B10B code, and is ‘payload only’.  That is, it is permitted to package this into a protocol-compliant string for test purposes.

http://www.t11.org/ftp/t11/pub/fc/pi-4/06-787v0.pdf

The doc names this pattern ‘SJPAT’ but it has since been re-acronymed ‘JSPAT’.  (Don’t ask.  ;-)

Regards,

Mike

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From: owner-t10@t10.org [mailto:owner-t10@t10.org] On Behalf Of Alvin.Cox@seagate.com
Sent: Thursday, September 27, 2007 12:05 PM
To: t10@t10.org
Subject: Measurement criteria for transmitter common mode voltage limit (Figure 118 of 07-339r5)

Measured with 1 MHz resolution bandwidth.
Range of 100 MHz to 6 GHz. The end points are at the center of the measurement bandwidth.
What data pattern? CJTPAT. It would be better with a spectrally flat pattern. Investigate SAS options to achieve this. Idle mode with random scrambled data?

Alvin Cox
Seagate Technology, LLC
Office 405-381-8067
Cell 405-206-4809
E-Mail  alvin.cox@seagate.com