[ibis-macro] Re: Tx_Jitter and Tx_DCD
- From: Ambrish Varma <ambrishv@xxxxxxxxxxx>
- To: "ibis-macro@xxxxxxxxxxxxx" <ibis-macro@xxxxxxxxxxxxx>
- Date: Fri, 9 Aug 2013 08:36:29 -0700
Todd,
While it is true that all the Reserved Parameters are Usage Info or Out in the
current spec, it is not mandated that ALL Reserved Parameters are going to be
of Usage Info or Out. Case in point are proposed Reserved Parameters in the
dependency BIRD and at least one InOut Reserved Parameter in the Backchannel
BIRD.
Thanks,
Ambrish.
From: ibis-macro-bounce@xxxxxxxxxxxxx [mailto:ibis-macro-bounce@xxxxxxxxxxxxx]
On Behalf Of Todd Westerhoff
Sent: Friday, August 09, 2013 11:28 AM
To: ibis-macro@xxxxxxxxxxxxx
Subject: [ibis-macro] Re: Tx_Jitter and Tx_DCD
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
[cid:image001.gif@01CE94F4.91F70860]Kumar 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<mailto: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<mailto: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<mailto: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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