What is IBIS-AMI?
The IBIS A
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.
SiSoft Leadership in IBIS-AMI
SiSoft has been a driving force in IBIS-AMI 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
- Intro to IBIS-AMI Tutorial, presented at DesignCon 2018
- A Beginner's Guide to SerDes AMI Modeling, DesignCon 2017
- IBIS-AMI: Assumptions, Terminology & Analytical Flows, IBIS Summit, DesignCon 2017
- Accurate AMI Analysis - Whose Responsibility Is It?, DesignCon 2016
- Two for One: Leveraging SerDes Flows for AMI Model Development, DesignCon 2016
- Building IBIS-AMI Models from Datasheet Specifications, DesignCon 2016
- Understanding IBIS-AMI Simulations, DesignCon 2015
- Improving IBIS-AMI Model Accuracy: Model-to-Model and Model-to-Lab Correlation Case Studies, DesignCon 2014
- Measurement-based Simulation: Increasing IBIS-AMI Model Accuracy with Data from Lab Measurements: DesignCon 2013
- Example Test Bench (Download) from DesignCon Tutorial, AMI Models: How to Tell a Peach from a Lemon
- AMI Models: How to Tell a Peach from a Lemon (pdf)
- Modeling Analog Repeaters in IBIS-AMI, DesignCon IBIS Summit, February 2011
- AMI Backchannel Co-Optimization - DesignCon IBIS Summit, February 2011
- Experiences Correlating IBIS-AMI Models and Measurement - DesignCon IBIS Summit, Feb 2010
- IBIS-AMI Termninology Overview - DAC IBIS Summit, July 2009
- Creating Broadband Analog Models for SerDes Applications - DesignCon 2009 IBIS Summit, Feb 2009
- System-level Serial Link Analysis using IBIS-AMI Models - Shanghai & Tokyo IBIS Summits, Nov 2008
- SerDes Modeling: IBIS-AMI Correlation - DAC IBIS Summit, 2008
- IBIS-AMI Correlation and BIRD Update - IBIS-ATM Working Group, April 2008
- SerDes Modeling: Demonstrating IBIS-AMI Model Interoperability - DesignCon IBIS Summit, Feb 2008
- SiSoft's IBIS-AMI Model Evaluation Toolkit - Beijing & Tokyo IBIS Summits, Sept 2007
- IBIS-AMI Modeling Proposal Status Report - Beijing & Tokyo IBIS Summits, Sept 2007
- IBIS-ATM Model Validation - IBIS-ATM task group, July 2007
- IBIS-ATM SerDes Modeling Status Report - DAC IBIS Summit, 2007
- IBIS-ATM Modeling Proposal - DesignCon IBIS Summit, 2007
- IBIS-ATM SerDes Modeling Status Report - DesignCon IBIS Summit, 2007
- Serial Link Modeling Terminology - IBIS-ATM Sub-committee, 2006
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 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"