Hello, Venu, Problems modeling delay changes with supply changes is a known "feature" of IBIS. The IBIS Open Forum is actively working on this. BIRDs 95.6, 97.2, and 98 are part of the solution. BIRD 95.6 was recently approved. User input is important in addressing timing issues. You would be welcome to attend the IBIS Open Forum and IBIS Futures meetings. For more info on these meetings (agenda, teleconference passcodes) please contact the IBIS chair, Michael Mirmak (michael.mirmak@intel.com). Best regards, Lynne _____ From: owner-ibis@eda.org [mailto:owner-ibis@eda.org] On Behalf Of Ummalaneni, Venu Babu (Venu) Sent: Tuesday, February 07, 2006 2:57 AM To: ibis-users@eda.org; ibis@eda.org Cc: Kotikalapudi, Shiva Kumar (Shiva) Subject: [IBIS] To capture the delay variation with change in IO voltage Hi Gurus, I have generated an IBIS model using rated IO voltage(1.5V) and simulated it at the same IO voltage(1.5V); the matching between hspice vs IBIS is very good (1st waveform in attached *.pdf). When I simulated the same IBIS model with reduced IO voltage (1.1v), the matching is poor (2nd waveform) between IBIS and hspice models. IBIS model is not able to capture the delay variation with supply voltage variation. Next, I have re-generated the IBIS model with reduced IO voltage(1.1V) and the simulation at this voltage(1.1V) gives good matching (3rd waveform) between IBIS and hspice models. Means IBIS model can not be used to see the variation in delay with the ripples on IO voltage? Is it known limitation? Are there any techniques/methods exist to build an IBIS model, which can be used to simulate at an IO voltage lesser/greater than the voltage at which it is build? Here, I am attaching a PDF of the waveforms I observed. Could some one help me in clarifying the above queries? Thanks in advance. Best Regards, Venu <<ibis_hspice_delay.pdf>> ----------------------------------------------------------------- |For help or to subscribe/unsubscribe, email majordomo@eda.org |with the appropriate command message(s) in the body: | | help | subscribe ibis <optional e-mail address, if different> | subscribe ibis-users <optional e-mail address, if different> | unsubscribe ibis <optional e-mail address, if different> | unsubscribe ibis-users <optional e-mail address, if different> | |or email a request to ibis-request@eda.org. | |IBIS reflector archives exist under: | | http://www.eda.org/pub/ibis/email_archive/ Recent | http://www.eda.org/pub/ibis/users_archive/ Recent | http://www.eda.org/pub/ibis/email/ E-mail since 1993Received on Tue Feb 7 08:06:45 2006
This archive was generated by hypermail 2.1.8 : Tue Feb 07 2006 - 08:11:58 PST