Subject: True or False?

From: Chris Rokusek <[email-masked]>
Date: Wed, 07 Oct 1998 16:15:07 -0700

Ibisians,

I have a Quiz, True or False:

The models of pins referenced by a [Diff Pin] keyword may NOT be of any
of the following:

    Terminator,
    Series, 
    Series_switch.

Chris

I think the spec implicitly says TRUE...

|=============================================================================
|     Keyword:  [Diff Pin]
|    Required:  No
| Description:  Associates differential pins, their differential
threshold
|               voltages, and differential timing delays.
|  Sub-Params:  inv_pin, vdiff, tdelay_typ, tdelay_min, tdelay_max
| Usage Rules:  Enter only differential pin pairs.  The first column,
[Diff
|               Pin], contains a non-inverting pin name.  The second
column,
|               inv_pin, contains the corresponding inverting pin name
for
|               I/O output.  Each pin name must match the pin names
declared
|               previously in the [Pin] section of the IBIS file.  The
third
|               column, vdiff, contains the specified output and
differential
|               threshold voltage between pins if the pins are Input or
I/O
|               model types.  For output only differential pins, the
vdiff
|               entry is 0 V.  The fourth, fifth, and sixth columns,
|               tdelay_typ, tdelay_min, and tdelay_max, contain launch
delays
|               of the non-inverting pins relative to the inverting
pins. The
|               values can be of either polarity.
|
|               If a pin is a differential input pin, the differential
input
|               threshold (vdiff) overrides and supersedes the need for
Vinh
|               and Vinl.
|
|               If vdiff is not defined for a pin that is defined as
requiring
|               a Vinh by its [Model] type, vdiff is set to the default
value
|               of 200 mV.
|
| Other Notes:  The output pin polarity specification in the table
overrides
|               the [Model] Polarity specification such that the pin in
the
|               [Diff Pin] column is Non-Inverting and the pin in the
inv_pin
|               column is Inverting.  This convention enables one 
[Model] to
|               be used for both pins.
|
|               Column length limits are:
|                  [Diff Pin]     5 characters max
|                  inv_pin        5 characters max
|                  vdiff          9 characters max
|                  tdelay_typ     9 characters max
|                  tdelay_min     9 characters max
|                  tdelay_max     9 characters max
|
|               Each line must contain either four or six columns.  If
"NA" is
|               entered in the vdiff, tdelay_typ, or tdelay_min columns,
its
|               entry is interpreted as 0 V or 0 ns.  If "NA" appears in
the
|               tdelay_max column, its value is interpreted as the
tdelay_typ
|               value.  When using six columns, the headers tdelay_min
and
|               tdelay_max must be listed.  Entries for the tdelay_min
column
|               are based on minimum magnitudes; and tdelay_max column,
|               maximum magnitudes.  One entry of vdiff, regardless of
its
|               polarity, is used for difference magnitudes.
|-----------------------------------------------------------------------------
[Diff Pin]  inv_pin  vdiff  tdelay_typ tdelay_min tdelay_max
|
 3           4       150mV    -1ns       0ns      -2ns  | Input or I/O
pair
 7           8         0V      1ns        NA        NA  | Output* pin
pair
 9          10         NA       NA        NA        NA  | Output* pin
pair
16          15       200mV     1ns    | Input or I/O pin pair
20          19         0V       NA    | Output* pin pair, tdelay = 0
22          21         NA       NA    | Output*, tdelay = 0
                                      | * Could be Input or I/O with
vdiff = 0
|
|======================================================================

---

From: Kellee Crisafulli <[email-masked]>
Date: Thu, 08 Oct 1998 12:22:56 -0700

It is TRUE,

>|               polarity, is used for difference magnitudes.
---------------------------------------------------------
Have a great day....
Kellee Crisafulli at HyperLynx
SI,EMC,X-talk and IBIS tools for the Windows platform
E-mail: <mailto:[email-masked]>
web:    <http://www.hyperlynx.com>
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