BIRD 2

Hey you IBIS type guys you,

Here is the original text for BIRD 2. We had some discussion on this
at the last phone call and I believe we will be having more at the
upcoming face to face. I would be willing to drop this issue in
exchange for a more sweeping "input thresholds" spec, or not.

jon

                 Buffer Issue Resolution Document (BIRD)

BIRD ID#: 2
ISSUE TITLE: Requiring VIH VIL thresholds for input devices
REQUESTOR: Jon Powell, Quad Desgin

DATE SUBMITTED: 10/4/93
DATE ACCEPTED BY IBIS OPEN FORUM: {will be filled in when accepted}

*******************************************************************************
*******************************************************************************

STATEMENT OF THE ISSUE:

        The V1.1 IBIS specification does not require the presence of input
        thresholds on input devices. This allows data-generators to omit
        thresholds and still create "IBIS LEGAL" models. Input devices with
        no stated digital logic input thresholds would only be usefull if the
        inputs were totaly analog devices (a condition that is not in the
        main-stream of IBIS targetted devices). Requiring a low and high threshold
        for all input devices is therefor a reasonable requirement that adds
        information without creating undo restrictions.

*******************************************************************************

STATEMENT OF THE RESOLVED SPECIFICATIONS:

        No new keywords are required.

        The following text to be added to the Other Notes section of the
        [Model] keyword description:
        
        The sub-parameters Vinl and Vinh are required for Model_types of:
        "Input" and "I/O". Omission of Vinl or Vinh for these devices will
        cause a parser error. Any other device type that contains a Vinl or Vinh
        parameter will cause a parser warning.

*******************************************************************************

ANALYSIS PATH/DATA THAT LED TO SPECIFICATION:

        There are devices that are not Input or Outputs and are not handled by
        our current set of model types. For instance:

        Termination Resistor Packs
        Termination Diode Packs
        Descrete 2 port devices

        I believe that more change is needed in this particular area but that that
        change is large enough that we should discuss it at our meeting as opposed
        to random email messages.

*******************************************************************************

ANY OTHER BACKGROUND INFORMATION:

      {These documents will be archived, so use this section to carry any detail
       that is not essential to the previous section, but should not be lost.}

*******************************************************************************
Received on Mon Nov 1 17:13:57 1993