David, It was specifically requested by the EDA vendors that the EDA tool only use the results of these Out parameters from Init, and specifically not from GetWave. It is also an outstanding issue whether these should be allowed as Out at all, and that we allow Info only. We have not seen any request (or need) for them to be Out parameters, so I do not object if they are Info only. The only reason I allowed Out was because Tx_DCD (in IBIS 5.0) was allowed to be Out, and I was consistent with that. The only parameter that must be allowed to be Out is Rx_Noise, and in this case it must be allowed as an Out from GetWave. It turns out that the amount of Rx_Noise that needs to be applied by the EDA tool is a function of the Gain inside of the AGC in the Rx model. Since it is an "AGC", the Rx GetWave can (and does) change the Gain which changes Rx_Noise which needs to be accounted for in the EDA tool. Walter From: David Banas [mailto:DBanas@xxxxxxxxxx] Sent: Tuesday, December 06, 2011 5:28 PM To: 'Walter Katz'; 'James Zhou' Cc: 'IBIS-ATM' Subject: Some final questions on BIRD 123. Hi Walter, I think I'm just about there. Just a couple of questions: 1. Referring to this excerpt from the most recent version of the BIRD (123.3_Draft1): Note: The EDA Tool/Simulator shall use the values of these Jitter and Noise parameters directly if they are Usage Info. If they are Usage Out, then the EDA Tool/Simulator shall use their values generated by AMI_Init. The model's AMI_GetWave function may return different values for these parameters than the values returned by AMI_Init; the EDA Tool/Simulator may report the values of such parameters to the user, but the EDA Tool/Simulator may not change any inputs to AMI models or change other result of the simulation based on the values returned for the parameters in this BIRD by AMI_GetWave. a. Why is there a necessary difference in EDA tool behavior, depending upon whether the parameters are of type Info or Out? b. If Init and GetWave can return different values for these parameters, then why do we need 2 sets (i.e. - Rx_Sj and Rx_CDR_Sj)? It seems like we ought to be able to have just one parameter, Rx_Sj, and let Init return one value for it, while GetWave returns another, depending upon how sophisticated its CDR modeling is. c. Referring to the last phrase, above, "or change other result of the simulation based on the values returned for the parameters in this BIRD by AMI_GetWave.": broadly interpreted, couldn't this phrase preclude an EDA tool from applying the post-processing necessary for accurate BER estimation? What is the purpose of this phrase? Thanks, -db _____ Confidentiality Notice. This message may contain information that is confidential or otherwise protected from disclosure. If you are not the intended recipient, you are hereby notified that any use, disclosure, dissemination, distribution, or copying of this message, or any attachments, is strictly prohibited. If you have received this message in error, please advise the sender by reply e-mail, and delete the message and any attachments. Thank you.