Physical ALF conference call, July 11 1:30PM - 3:00PM

Attendees:

Fereshteh Kianersi	Synopsys
Simon Favre		Monterey
Joe Daniel		Intrinsix
Paul Zukowski		IBM
Wolfgang Roethig	NEC

The general ALF spec and the physical ALF spec have been edited.
Reviewed the section "arithmetic models" from the general ALF
spec and the section "physical modeling", which is basically the
physical ALF spec. The section "arithmetic models" is relevant for
both physical and non-physical ALF.

The following changes were proposed during review:

Semantics of HEIGHT and WIDTH
-----------------------------

HEIGHT:	Measured in Y direction for placable object.
	Measured in Z direction for routable object, 
        where it means absolute height over substrate.

WIDTH:	Measured in X direction for placable object.
	Measured in X or Y direction for routable object,
        whichever direction is orthogonal to routing.

Values for PURPOSE of LAYER
---------------------------

Replace "master" by "substrate".
Introduce "dielectric", meaning passivation layer.

Geometric transformations of ARTWORK
------------------------------------

Old:	Only ROTATE and SHIFT are allowed.
New:	Allow FLIP as well.

Routing PREFERENCE
------------------
Old:	Weighting factors for VERTICAL and HORIZONTAL.
New:	Specify just VERTICAL or HORIZONTAL,
	no weighting factors

MIN/TYP/MAX for WIDTH in routing LAYER
--------------------------------------

Semantics need clarification:
In this context it means manufacturing tolerance
of the specified default WIDTH.
MIN/MAX meaning boundaries of legal range would be
in the context of a RULE statement.

Context of geometric model
--------------------------

Old:	Geometric model is in context of PATTERN, BLOCKAGE or PORT
New:	Geometric model is in context of PATTERN only.
	To define geometric models within BLOCKAGE or PORT or any 
	other object, PATTERN has to be defined within that object

Stacked via
-----------

Old:	Term "top_of_stack" was used instead of LEF "topOfStackOnly".
New:	Term "stack_only" is used instead of LEF "topOfStackOnly".

Issue: Neither term describes exactly the meaning.
The meaning of "topOfStackOnly" is: Via is to be used only
for construction of stacked via, except for the bottom.
A regular via can be usedfor the bottom.
So, a concise term would be "stack_only_except_for_bottom",
but this is too lengthy.
Other layout tools may use different construction rules anyway.
Conclusion: leave it as is for the time being, but add explanation.