Re: VINH and VINL

*** My comments look like this *****, Randy Harr

> From intelhf.intel.com!ccm!Don_A_Telian@lmc.com Thu Oct 7 17:15:10 1993
> To: Will_Hobbs@ccm.hf.intel.com, Arpad_Muranyi@ccm.hf.intel.com, qdt!sal!jonp,
> ibis@vhdl.org
> Subject: Re: VINH and VINL
> Content-Length: 1518
> X-Lines: 42
>
>
> >>>> Howdy, My comments look like this >>>>> , Don Telian
> >>>> Jon Powell's original memo follows....
>
>
> Fellow IBIS type persons,
>
> At the recent IBIS phone call I volunteered to author a BIRD on the
> subject of requiring VINH and VINL specifications for input devices.
> This was to avoid the problem of useless but IBIS legal input devices
> with no logic threshold. Upon studying the problem I noticed that there
> is actually a larger change required than I had anticipated and I
> believe I should solicit comments before I actually write the BIRD.
> The problem is two fold:
>
> First. I believe that our current model-types are not sufficiently
> exclusive. We have INPUT OUTPUT I/O 3-STATE and OPEN_DRAIN. Under
> what category does a 3-state I/O fall?
>
> >>>>> If it's "i/o", it's got to be "3-state", unless it intends
> >>>>> to only drive itself. Right? Consequently, "3-state I/O"
> >>>>> and "I/O" are the same thing.
>
**** No, could be input with open collector and maybe a PUP resistor internal.
**** Siuki and I have been having many discussions in this area and feel it
**** needs to be clarified between active and passive drivers. Once this is
**** done, seemingly simple items like signal direction become clearer to
**** define and understand.

**** rest of message cut; no additional comment form me
Received on Fri Oct 8 01:59:55 1993