Reminder: SAS PHY teleconference 5/31/07, 10 am CDT

Alvin.Cox at seagate.com Alvin.Cox at seagate.com
Wed May 30 15:14:30 PDT 2007


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Topic: SAS-2 PHY WG 
Date: Thursday 
Time: 10:00 am, Central Daylight Time (GMT -05:00, Chicago) 
Meeting number: 826 515 680 
Meeting password: 6gbpsSAS 
Agenda: 
1. Receiver jitter tolerance [Jenkins] 
Mike to provide a working draft to discuss. 
2. SAS-2: Improving a Jitter Definition (07-205) 
http://www.t10.org/ftp/t10/document.07/07-205r0.pdf 
Comments from Bent Hessen-Schmidt, SyntheSys Research, Inc.: 
I suggest that we use text equivalent to: 
The Reference Clock characteristics are controlled by the resulting JTF 
(Jitter Transfer Function) characteristics obtained by taking the time 
difference between the PLL output (the Reference Clock) and the data 
stream sourced to the PLL. The PLL CLTF -3 dB corner frequency, and other 
adjustable CLTF parameters such a peaking, are determined by the value 
required to meet the requirements of the JTF. 
The JTF shall have the following characteristics for an encoded D24.3 
pattern (1100110011 0011001100). This is the MFTP which is a test pattern 
that has clock-like characteristics and a transition density of 0.5. 
1) The -3 dB corner frequency of the JTF shall be 3 MHz +/-1 MHz. 
2) The magnitude peaking of the JTF shall be 3.5 dB maximum. 
3) The attenuation at 30 KHz +/-1% shall be 75 dB +/-3 dB. 
The JTF -3dB corner frequency and the magnitude peaking requirements shall 
be measured with sinusoidal PJ applied, with a peak-to-peak amplitude of 
0.3 UI +/-10%. The relative attenuation at 30 KHz shall be measured with 
sinusoidal phase (time) modulation applied, with a peak-to-peak amplitude 
of 20.8 ns +/-10%. 
You will see that we have changed to from 72 db to 75 dB and from 2.1 MHz 
to 3 MHz and added the word “relative” to the last sentence. Relative 
should indicate that the 75 dB are with respect to the actual magnitude of 
jitter on the 30 kHz stimulus. The +/-10% therefore merely sets the 
starting point and still allows the other vendor. All uncertainties are 
then included in the +/-3 dB term. Effective tightening of the tolerances 
can be seen on the residual of the 30 kHz being confined to less than 5.2 
ps instead of (7.4 x 1.1 x 1.1 ps = 8.95 ps). 
3. SAS-2 Channel StatEye Simulation Results (07-253) [Witt] 
http://www.t10.org/ftp/t10/document.07/07-253r0.pdf 
Status: 
* Galen is to send Harvey a 10-meter Mini SAS cable. Harvey will post data 
|from actual hardware in the near future. 
* Harvey will continue to forward StatEye questions to Anthony Saunders to 
improve the model. 
* Mike Jenkins suggested some settings to help the simulation set-up. 
Kevin will try. 
4. Additional items and updates. 
     10-meter cable specification
     zero-length test load
Alvin Cox
Seagate Technology, LLC
Office 405-381-8067
Cell 405-206-4809
E-Mail	alvin.cox at seagate.com



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