Library harmonization meeting October 11 2004
at Cadence, San Jose

Attendees
---------
Koorosh Nazifi	Cadence
Jim McCanny	Cadence
John Williams	Markanix
Wolfgang Roethig	NEC
Andrea Cosmin	Artisan (phone)
Albert Ting	Artisan (phone)
Maddu Karutaratne	V-cube


Action item status
------------------

Make list of liberty items for which ALF representation is unknown
Owner: Fereshteh/Kevin
WIP
Main areas: power, flow-specific representation
Kevin: Rajesh has a partial list, Kevin will send it out by May 7.
Kevin reminded Rajesh, please send as early as possible.
Will get it done before next meeting (July 12)
(hopefully) WIP

Write short elaboration on requirements noise items (see DoD section 2.4)
Owner: Matt Liberty
WIP - Cadence discussions ongoing
Reassigned to Bhuwnesh/Koorosh, Koorosh will give update by May 7.
Will get update by June 25
WIP
Cadence committed to report their requirements in August 2004 meeting
Cadence reported in October meeting
DONE

Investigate propagation delay concept (rise_transition, fall_transition).
Give example in ALF.
Owner: Wolfgang
OPEN
Look for rise_propagation, fall_propagation keywords in liberty spec
Wolfgang looked for semantic description or example in liberty doc 2003.10,
but could not find.
Kevin sent a doc with description to Wolfgang.
Wolfgang updated timing document
DONE

Is the functional equivalence in the equal_or_opposite_output rule enforced,
or can the model with 2 output capacitances also be used for any cell with
2 outputs, given an arc-specific condition? What about applicability for timing?
Example: cells with functionally correlated outputs, but not strictly
equivalent or complementary.
Owner: Kevin
For timing, the keyword is related_output.
Need to know whether equal_or_opposite_output is supported for full adder.
Co-owner: Hemant
WIP

Document glitch and switching activity modeling in ALF
Owner: Wolfgang
Wolfgang updated power document
DONE

Discuss and document SDF LABEL usage
Owner: Wolfgang (all)
Wolfgang updated timing document
DONE

Provide dont_use, dont_touch, dont_fault doc to working group
Reason: dont_use, dont_touch, dont_fault not documented in liberty doc
Need Synopsys tool document, which is not available for everybody
Owner: Kevin Kranen
WIP
Wolfgang got document from Synopsys, reviewing

scan_group not described in liberty doc.
Find other doc for work group.
Owner: Kevin
OPEN

Describe example for clock-gating cell
Owner: Hemant
OPEN
Question: which application tool will use the statetable?
Why not use the "latch" statement?

New action items
----------------

Investigate how to express "canfloat", "cannotfloat" in liberty and ALF
Owner: John Williams
NEW

Follow-up questions to Jim McCanny
udn library or design-specific?
canfloat for any pin or only for output pin?
Owner: Wolfgang
NEW

Next meeting
------------
Wolfgang will propose a date for the next meeting in Nov., hosted by NEC

Technical discussion on SI requirements
=======================================

Topics
------
- input noise filtering
- driver characteristic (hold/driver)
- noise propagation

Cell properties
---------------
- is_cell, is_filler_cell
Liberty: missing (?)
ALF: CELLTYPE=special, ATTRIBUTE { fillcell }

Pin properties
--------------
- input,output,bidir
Liberty and ALF: same

- unbuffered
Liberty: missing (?)
ALF: use DRIVETYPE annotation, gives more detailed information

- canfloat, cannotfloat
Liberty: missing (?)
ALF: need to establish rules based on DRIVETYPE
     (e.g. cmos input cannot float, tristate pin can float etc.)

Input noise filtering
---------------------
- low and high tolerance (noise below tolerance is ignored)
Liberty: noise_immunity or hyperbolic_noise (?)

- pin capacitance (steady state)
Liberty: pin cap can be for rise and fall, default should be same
ALF: pin cap can be for rise and fall or vector-dependent, default should be same

- associated supply names and values (power/ground)
Liberty: missing (?)
ALF: use SUPPLY_CLASS annotation

Driver characteristic
---------------------
- IV curves: output current = f(input voltage, output voltage),
  voltage measured to reference (vdd or gnd)
Liberty: IV curves only 1D, i.e. f(output voltage)
ALF: IV curves support 1, 2, or more dimensions

- driver resistance
Liberty: steady_state_resistance_low|_high
ALF: state-dependent driver resistance supported

Glitch propagation
------------------
- not precharacterized, using transistor-level analysis on the fly
- reason: non-linearity, simultaneous noise on multiple input ...
Liberty: precharacterization supported
ALF: precharacterization supported

User-defined noise model (udn)
------------------------------
noise source at output pin
Library or design-specific model?

Spice subcircuits
-----------------
out of scope for Liberty and ALF, but need
xref capability between transistor files and cell files
Liberty: not supported
ALF: ASSOCIATE statement can be used
Need to add values to the FORMAT annotation:
SPICE (.sp), Liberty (.lib), ASCII text (.txt)

New requirements for 90nm and below
-----------------------------------
IV-curves, drive resistance etc should support more dimensions,
especially process variations (width, thickness etc) and temperature