IBIS Model Verification

This service offers:

  • Visual Inspection of the IBIS file
  • Checks for completeness, presence and monotonicity of all waveforms
  • Test simulation using a standard load and user defined test loads (optional)
  • Verification of the test simulation results with customers
  • Checking, definition or modification of the package data where required
  • Contact and negotiation with the IC vendor
  • Correction of the IBIS file, working in conjunction with customers

Problem Description

IBIS (Input Output Buffer Information Specification - http://www.eigroup.org/ibis ) is an ANSI/EIA standard method of providing the Input/Output device characteristics through V/I data without disclosing any circuit/process information. It can be seen as a behavioral modeling specification suitable for transmission line simulation of digital systems and applicable to most digital components.

The core of the IBIS model consists of a table of current versus voltage and timing information. This is very attractive to the IC vendor as the IO internal circuit is treated as a black box. That way, transistor level information about the circuit and process details are not revealed. IBIS models are now commonplace for signal integrity simulations and can be used in a wide range of EDA tools. However, many IC vendors have been reluctant to fully support the standard. There are two main reasons for this. Firstly, there is a lack of software to both automate and verify the IBIS modeling syntax at the commercial level. Secondly, there is a wide gap between IC manufacturers' SPICE models and IBIS tools. SPICE is the IC industry's standard for transistor modeling and IBIS models are produced by translating SPICE models. As a result of the translation process, many IBIS files are of poor quality, to the extent that large numbers are of little use. It is also difficult for users to judge the quality of these models in the first instance.
Users can verify IBIS modules using appropriate tools but a more cost-effective solution for many will be to use the new Zuken high-speed pcb design consulting service for IBIS model verification.

Further Keys to Success in High-Speed Board Design - Reliable Simulation Models

Even if the Zuken Lightning IBIS-Import (which is based on the official IBIS 3.2 golden parser from the IBIS Open Forum) is an IBIS compliant tool to address these issues, users may lack either time or knowledge to verify their IBIS files. The returned IBIS model produced is guaranteed to work properly with Zuken analysis tools (provided it is compliant to the standard and useful by its content). On demand the various curves embedded in the model and test simulation results would be provided in a report. As some simulators cannot account for non-monotonic behavior or sudden changes in the I/V characteristics, these would be corrected (with notify in the file). These service makes the Zuken IBIS Verification Service an ideal complementary offer to your high speed design process.

The Zuken IBIS Verification Service supports all IBIS format revisions up to IBIS 3.2.