What is IBIS-AMI?

IBIS-AMI Datasheet (PDF)


The IBIS Algorithmic Modeling Interface (IBIS-AMI) is a modeling standard for SerDes PHYs that enables fast, accurate, statistically significant simulation of multi-gigabit serial links. IBIS-AMI was developed by a consortium of EDA, Semiconductor and Systems companies and was approved as part of the IBIS 5.0 Specification in August 2008.


Before IBIS-AMI, systems designers faced significant limitations when performing serial link simulations:

  • Traditional SPICE-based analysis is slow and can't simulate the millions of bits needed to accurately predict link operating margins
  • Open-source statistical analysis tools simulated many millions of bits but couldn't accurately model a specific semiconductor vendor's device IP
  • Proprietary semiconductor vendor tools accurately model vendor IP and simulate millions of bits, but can't be used when different semiconductor vendors are used at each end of the link

The IBIS-AMI specification was developed with the following specific goals:

  • (Interoperability) Models from different semiconductor vendors work together
  • (Transportability) The same model runs in different IBIS-AMI simulators
  • (Performance) 10 million bit simulations run in 10 minutes or less
  • (Flexibility) Models support both Statistical and Time-Domain simulation
  • (Usability) Models expose control parameters users can set for simulation
  • (IP Protection) Models cannot be reverse-engineered, semiconductor vendors control which details are exposed to the user

IBIS-AMI models make multi-million bit simulations practical, accurately model vendor-specific equalization and clock recovery algorithms and make mixed-vendor analysis quick and easy. IBIS-AMI allows commercial channel simulators to provide the same levels of performance and accuracy as proprietary semiconductor vendor tools.

IBIS-AMI Datasheet (pdf)


Intro to IBIS-AMI Tutorial (Presented at DesignCon 2018)




IBIS-AMI Update, Real Time with DesignCon 2011, PCBDesign007 (VIDEO)

IBIS-AMI Datasheet (PDF)


SiSoft has been a driving force in IBIS-AMI MODEL SIMULATION since its inception in 2006. SiSoft led the definition of the analysis terminology, simulator/model interface, model control (.AMI) file syntax, reference flow and design documents (IBIS BIRDs 104 and 107) that created the specification as it exists today.


Unique SiSoft contributions to IBIS-AMI include:

SiSoft is an active member of the IBIS Open Forum and is strongly committed to the development of open modeling standards. We are currently collaborating with over 15 different Semiconductor companies to develop and correlate IBIS-AMI models. SiSoft is committed to the ongoing enhancement of IBIS-AMI, working with its Semiconductor Partners and the IBIS committee to enhance the IBIS-AMI specification to meet the needs of 20 Gb/s and beyond.


If you're looking to have IBIS-AMI models developed or learn how to develop them yourself, SiSoft offers a full range of IBIS-AMI model development and training services to get you up and running. We've developed and correlated more IBIS-AMI models than anyone, and we can teach you how to develop IBIS-AMI models as well.


Material presented by SiSoft on IBIS-AMI

IBIS-AMI Simulation Toolkit


IBIS Algorithmic Modeling Interface (AMI) models provide a standard mechanism for modeling transmit / receive equalization and clock recovery algorithms for SerDes devices. The IBIS-AMI specification allows a serial channel to be "characterized" using circuit simulation techniques; that channel characterization is then combined with signal processing techniques and IBIS-AMI models to predict the link's behavior over millions of bits of data. IBIS-AMI models represent equalization and clock recovery algorithms using executable code - the use of a "black box" technique permits fast modeling of device behavior and also helps protect semiconductor vendor IP.


This free toolkit contains a sample IBIS-AMI 4-tap transmitter model in both binary and executable form along with the IBIS_AMI_test utility. IBIS_AMI_Test allows IBIS-AMI models to be run as standalone executables from the O/S command line. This toolkit also includes sample data and batch jobs - everything you need to demonstrate the speed and flexibility these models have to offer.


Download the SiSoft IBIS-AMI toolkit (Version 2.21)


Download the sample

  • IBIS-AMI model only IBIS file (Save As sisoft_tx.ibs)
  • AMI file (Save As IBIS_AMI_Tx.ami)
  • Algorithmic model (Save As IBIS_AMI_Tx.dll)

Download the Example Test Bench from the DesignCon 2012 tutorial, AMI Models: How to Tell a Peach from a Lemon"