[ibis-macro] Re: Tx_Jitter and Tx_DCD

  • From: "Todd Westerhoff" <twesterh@xxxxxxxxxx>
  • To: <ibis-macro@xxxxxxxxxxxxx>
  • Date: Fri, 9 Aug 2013 11:27:38 -0400 (EDT)

Greg,



Reserved Parameters are Usage Info, which means the data is not presented to 
the algorithmic model.  In the IBIS 5.1 spec, see “Reserved Parameters 
Reference” beginning on page 183.



Tx_Jitter and Tx_DCD are processed by the simulator, although the spec doesn’t 
define the details of what the simulator does.  It declares what the jitter 
represents and how it is defined.  Simulators are thus able to use different 
methods, whether it be pre-processing of the input stimulus in time-domain 
simulation, post-processing in statistical simulation, or something more 
exotic.



Todd.



Todd Westerhoff

VP, Software Products

Signal Integrity Software Inc. • www.sisoft.com

6 Clock Tower Place • Suite 250 • Maynard, MA 01754

(978) 461-0449 x24  •  twesterh@xxxxxxxxxx



“I want to live like that”

                                             -Sidewalk Prophets



From: ibis-macro-bounce@xxxxxxxxxxxxx 
[mailto:ibis-macro-bounce@xxxxxxxxxxxxx] On Behalf Of Gregory R Edlund
Sent: Friday, August 09, 2013 11:06 AM
To: Kumar Keshavan; ibis-macro@xxxxxxxxxxxxx
Subject: [ibis-macro] Re: Tx_Jitter and Tx_DCD



Thank you, Kumar.

Is anyone aware of language in the specification saying that the EDA tool 
should apply Reserved_Parameters and not the algorithmic model (DLL)?  I 
need to know so I can instruct our internal model users on what to expect 
from the vendors they're working with.  We're looking at a case where it 
appears the vendor included transmitter jitter inside the DLL.  I don't see 
a problem with this as long as we know about it and we're not simulating the 
same jitter from both the DLL and the EDA tool.

Here's what I found in Section 10A, page 183.  By inference, the optional 
Reserved_Parameters should also be used by the EDA tool and not the 
algorithmic model.

RESERVED PARAMETERS REFERENCE

The parameter definition file shall have a branch with the heading 
“Reserved_Parameters”. This branch shall contain all the Reserved Parameters 
for the model.

The following Reserved Parameters are used by the EDA tool and are required 
if the [Algorithmic Model] keyword is present.


Greg Edlund
Senior Engineer
Signal Integrity and System Timing
IBM Systems & Technology Group
3605 Hwy. 52 N  Bldg 050-3
Rochester, MN 55901



Inactive hide details for Kumar Keshavan ---08/09/2013 09:44:11 AM---if they 
are in Reserved_Parameters it becomes the responsKumar 
Keshavan ---08/09/2013 09:44:11 AM---if they are in Reserved_Parameters  it 
becomes the responsibility of the eda tool __________________

From: Kumar Keshavan <ckumar@xxxxxxxxxxx>
To: Gregory R Edlund/Rochester/IBM@IBMUS
Date: 08/09/2013 09:44 AM
Subject: RE: [ibis-macro] Tx_Jitter and Tx_DCD

  _____





if they are in Reserved_Parameters  it becomes the responsibility of the eda 
tool

________________________________________
From: ibis-macro-bounce@xxxxxxxxxxxxx [ibis-macro-bounce@xxxxxxxxxxxxx] On 
Behalf Of Gregory R Edlund [gedlund@xxxxxxxxxx]
Sent: Friday, August 09, 2013 10:27 AM
To: ibis-macro@xxxxxxxxxxxxx
Subject: [ibis-macro] Tx_Jitter and Tx_DCD

I have a basic question about where Tx_Jitter and Tx_DCD are supposed to be 
applied during simulation:

Is the EDA tool supposed to apply Tx_Jitter and Tx_DCD, or is that up to the 
algorithmic model?



I was unable to find the answer in the following sections of IBIS 5.1. 
Maybe it's in another section that I missed.

Section 10.2.3.2, Time Domain Simulation Reference Flow, page 161

Section 10.2.2, Time Domain Simulations, page 160

Section 10A, Reserved Parameters Reference, page 187


Greg Edlund
Senior Engineer
Signal Integrity and System Timing
IBM Systems & Technology Group
3605 Hwy. 52 N  Bldg 050-3
Rochester, MN 55901



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