James, That digital stimulus has nothing to do with the impulse response of the channel. That is the input to the Tx AMI_GetWave function. But you are correct, the impulse response is differential. For example, if the impulse response is generated by taking the derivative of a step waveform observed at the Rx, the waveform that you would use is the difference waveform between the two traces of a differential pair. I hope this helps, Arpad ================================================================ From: ibis-macro-bounce@xxxxxxxxxxxxx [mailto:ibis-macro-bounce@xxxxxxxxxxxxx] On Behalf Of James Zhou Sent: Wednesday, July 11, 2012 2:08 PM To: wkatz@xxxxxxxxxx; gedlund@xxxxxxxxxx; 'IBIS-ATM'; ibis-macro-bounce@xxxxxxxxxxxxx Subject: [ibis-macro] Re: What part of Legacy IBIS is used by IBIS-AMI Walter, According to BIRD120, the digital stimulus has amplitude range of -0.5 to +0.5 and all transitions occur at zero crossing. Since this range mostly applies to differential signals, does it mean that the impulse response should also be differential impulse response? If the V-T curves are provided separately for pin+ and pin-, their impulse responses have to be obtained separately and then combined into a single differential impulse response. James From: ibis-macro-bounce@xxxxxxxxxxxxx<mailto:ibis-macro-bounce@xxxxxxxxxxxxx> [mailto:ibis-macro-bounce@xxxxxxxxxxxxx]<mailto:[mailto:ibis-macro-bounce@xxxxxxxxxxxxx]> On Behalf Of Walter Katz Sent: Wednesday, July 11, 2012 7:40 AM To: gedlund@xxxxxxxxxx<mailto:gedlund@xxxxxxxxxx>; 'IBIS-ATM'; ibis-macro-bounce@xxxxxxxxxxxxx<mailto:ibis-macro-bounce@xxxxxxxxxxxxx> Subject: [ibis-macro] Re: What part of Legacy IBIS is used by IBIS-AMI Greg, Yes, almost. You still need a voltage swing either extracted from the VT curves, Ramp data or [Voltage Range]. You would be assuming a zero rise time for the driver. This is equivalent to the simple Tx Analog Buffer Circuit described in BIRD 122. Walter From: ibis-macro-bounce@xxxxxxxxxxxxx<mailto:ibis-macro-bounce@xxxxxxxxxxxxx> [mailto:ibis-macro-bounce@xxxxxxxxxxxxx]<mailto:[mailto:ibis-macro-bounce@xxxxxxxxxxxxx]> On Behalf Of Gregory R Edlund Sent: Wednesday, July 11, 2012 10:15 AM To: 'IBIS-ATM'; ibis-macro-bounce@xxxxxxxxxxxxx<mailto:ibis-macro-bounce@xxxxxxxxxxxxx> Subject: [ibis-macro] Re: What part of Legacy IBIS is used by IBIS-AMI What if an EDA programmer wanted to discard the VT and ramp data and compute an "ideal mathematical" impulse response assuming a delta function? Is that allowed by BIRD 120? I took a quick look and didn't see anything specific about how to calculate the impulse response. In the "ideal mathematical" case, I would think all you need is C_Comp and some resistance extracted from the IV tables. 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 "Walter Katz" ---07/11/2012 03:53:30 AM---I agree.]"Walter Katz" ---07/11/2012 03:53:30 AM---I agree. From: "Walter Katz" <wkatz@xxxxxxxxxx<mailto:wkatz@xxxxxxxxxx>> To: <Arpad_Muranyi@xxxxxxxxxx<mailto:Arpad_Muranyi@xxxxxxxxxx>>, "'IBIS-ATM'" <ibis-macro@xxxxxxxxxxxxx<mailto:ibis-macro@xxxxxxxxxxxxx>> Date: 07/11/2012 03:53 AM Subject: [ibis-macro] Re: What part of Legacy IBIS is used by IBIS-AMI Sent by: ibis-macro-bounce@xxxxxxxxxxxxx<mailto:ibis-macro-bounce@xxxxxxxxxxxxx> ________________________________ I agree. Walter From: ibis-macro-bounce@xxxxxxxxxxxxx<mailto:ibis-macro-bounce@xxxxxxxxxxxxx> [mailto:ibis-macro-bounce@xxxxxxxxxxxxx] On Behalf Of Muranyi, Arpad Sent: Tuesday, July 10, 2012 11:44 PM To: IBIS-ATM Subject: [ibis-macro] Re: What part of Legacy IBIS is used by IBIS-AMI That is correct. Arpad ================ From: ibis-macro-bounce@xxxxxxxxxxxxx<mailto:ibis-macro-bounce@xxxxxxxxxxxxx> [mailto:ibis-macro-bounce@xxxxxxxxxxxxx]<mailto:%5Bmailto:ibis-macro-bounce@xxxxxxxxxxxxx%5D> On Behalf Of Mirmak, Michael Sent: Tuesday, July 10, 2012 6:07 PM To: Walter Katz Cc: IBIS-ATM Subject: [ibis-macro] Re: What part of Legacy IBIS is used by IBIS-AMI Walter, Thank you! So, someone using IBIS-AMI models with valid traditional data in a workflow should expect changes in the IBIS TX C_comp or V-t (or [Ramp]) data to have an impact on the results provided by the receiver in an IBIS-AMI-based flow, assuming nothing else changes? - MM From: Walter Katz [mailto:wkatz@xxxxxxxxxx]<mailto:%5Bmailto:wkatz@xxxxxxxxxx%5D> Sent: Tuesday, July 10, 2012 12:20 PM To: Mirmak, Michael Cc: IBIS-ATM Subject: What part of Legacy IBIS is used by IBIS-AMI MM, The Legacy part of an IBIS model is used to generate the Impulse Response of the channel. One method of generating the impulse response is to do a step response, and take the derivative of the waveform at the Rx input. A simulator uses a combination of the Tx [Voltage Range], C_Comp, IV, VT and Ramp data, and the Rx C_Comp and IV data. Of course, [External Model] can also be used by a simulator. The following required Tx IBIS fields are not used in the AMI flow: Vmeas The following required Rx IBIS fields are not used in the AMI flow: Vinl Vinh Walter Walter Katz wkatz@xxxxxxxxxx<mailto:wkatz@xxxxxxxxxx> Phone 303.449-2308 Mobile 303.335-6156 ________________________________ This message and any attached documents contain information from QLogic Corporation or its wholly-owned subsidiaries that may be confidential. If you are not the intended recipient, you may not read, copy, distribute, or use this information. If you have received this transmission in error, please notify the sender immediately by reply e-mail and then delete this message.