[ibis-interconn] IBIS Interconnect Task Group Oct. 6 Minutes and Oct. 13 Agenda
- From: "Mirmak, Michael" <michael.mirmak@xxxxxxxxx>
- To: IBIS-Interconnect <ibis-interconn@xxxxxxxxxxxxx>
- Date: Tue, 12 Oct 2010 22:15:05 -0600
======================================================================
IBIS INTERCONNECT TASK GROUP MEETING MINUTES AND AGENDA
http://www.eda.org/ibis/interconnect_wip/ (note new URL)
Mailing list: ibis-interconn@xxxxxxxxxxxxx<mailto:ibis-interconn@xxxxxxxxxxxxx>
======================================================================
Next Meeting
Wednesday, October 13, 2010
9 AM US Pacific Time
Telephone Bridge Passcode
916-356-2663 5 758-3581
(for international and alternate US numbers, contact Michael Mirmak)
LiveMeeting: https://webjoin.intel.com/?passcode=7583581
Agenda:
- Attendees
- Call for patents
- Review of Minutes
* Oct. 6, 2010
- Opens
- MCP Comments Review and live editing - add mixed-mode terms?
- Agenda for Next Meeting
- Approve Next Meeting Dates:
* Oct. 20, 2010
* Oct. 27, 2010
======================================================================
Minutes from October 6:
Attendees:
----------
(* denotes present)
Agilent - Radek Biernacki*, John Moore, Ken Wong
Ansoft - Denis Soldo
Cadence Design Systems - Terry Jernberg, Brad Griffin, Dennis Nagle,
Taranjit Kukal
Cisco Systems - Mike LaBonte
Green Streak Programs - Lynne Green
Hewlett-Packard - Rob Elliott
IBM - Greg Edlund
ICT-Lanto - Steven Wong
Intel - Michael Mirmak*
Mentor Graphics Corp. - Arpad Muranyi*, John Angulo*, Vladimir
Dmitriev-Zdorov
Micron Technology - Randy Wolff*, Justin Butterfield
Sigrity - Sam Chitwood, Raymond Y. Chen, Tao Su, Brad Brim*
SiSoft - Walter Katz*
Teraspeed Consulting Group - Bob Ross*
========================================================================
No patents were declared.
Michael Mirmak, during opens, mentioned several minor changes being made
to the format of agendas and procedures during meetings. These will
bring Task Group practices more into alignment with TechAmerica rules.
The team continued its edits of IBIS-ISS rev. 0.6, reviewing written
comments from Arpad Muranyi and Bob Ross.
Regarding ISS line continuation, Arpad suggested putting a separator
in the "cos" or in the "4.356789" number in the given example.
Radek Biernacki added that the syntax should support including a
space before the \\ as well.
Arpad suggested adding more numbers to the 32.67 sequence in the example.
Bob added a proposal to put \\ after cos and ( as well.
Arpad asked whether a lack of space is required.
Radek noted that using \ as a line continuation is acceptable, adding that
the entire expression in the example is not a token. Bob added that the
spaces in the expression are optional.
Arpad noted that, on p.28, parameter passing should be clarified regarding the
*definition* of a parameter. Radek added that you can only pass the *value*
of the parameter.
Arpad suggested that the writer can define a parameter on the subckt definition
line,
passing values when it's called. At least one proprietary SPICE variant has
an alternate way to do the same thing, with a .param statement *inside* the
subcircuit, while still having a mention of it when instantiating the
subcircuit.
In other words:
Method 1: parameter is defined on the .subckt line
Method 2: parameter defined as .param inside the subcircuit, but not on .subckt
line
Both of them can have instantiation statements using parameter names.
Examples are shown below:
METHOD 1
.subckt TEST n1 n2
.param myparam=5
...
.ends
Xexample 5 6 TEST myparam=2
METHOD 2
.subckt TEST n1 n2 myparam=5
...
.ends
Xexample 5 6 TEST myparam=2
Arpad suggested removing the section below denoted by ***:
A parameter is defined either by a .parameter statement (local to that
subcircuit),
***or may be passed into a subcircuit***, or may be defined on a .subckt
definition line.
Michael asked whether one may pass parameters both by position and by name.
Radek replied that this would not be desirable. Further, he expressed
reluctance
to permit omission of "R=" for resistor values. Arpad suggested that probably
one of the other HDLs supports this.
The team agreed that out-of-order passing and omission of parameters are both
permitted, as shown below:
.subckt TEST n1 n2 yourparam=2 myparam=5
...
.ends
Xexample 5 6 TEST myparam=2
Bob asked whether global parameters are permitted in IBIS-ISS if the calling
SPICE variant supports them.
Arpad replied that .global applies only to nodes, not params and that ISS
parameters are always local, not global.
All agreed that ISS does not permit definition of global parameters.
Michael asked whether, per Bob, the top-level tool can declare global
parameters that affect IBIS-ISS statements.
Radek suggested this was a question of parsing; he suggested keep ISS separate
from the rest of the netlist's assumptions.
Arpad added that this was also an engine issue.
Radek observed that this situation is similar to a name conflict. Arpad
replied that this was slightly different, in
that, if we use the same parameter name in a subcircuit, it will be applied
locally. He asked whether an ISS subcircuit
may use a parameter without defining it explicitly. Michael suggested that
this would not be allowed, as ISS would be
self-contained.
Arpad asked whether ISS contains specific language about this. Bob stated that
if a parameter is used but not defined,
it's illegal (by the ISS parser).
Arpad suggested that further discussion is needed on user-defined global
parameters. Michael responded that
reserved global nodes (e.g., gnd) are defined; .global is prohibited from
applying within ISS, even if you have these
defined at the top-level SPICE. Bob suggested adding statements about this to
the last ISS section, with .param, as one
of the "things to avoid" (as a poor programming practice).
Arpad asked whether strict parsing is now being enforced for comment character
usage ( *, $).
Radek stated that, if an asterisk appears in the middle of the line, the writer
has commented out the rest of the line
(except for expressions involving *). Bob stated that he assumed a $ can be
the first character in a line.
Michael noted that, in response to a comment from Arpad, the current draft
removes scaling as defined by S=...
Arpad asked whether the M scaling factor is permitted. This was useful for
transistors, but may be less important for ISS.
AR: Michael to provide illustrations of line continuation that are more
meaningful
AR: Michael to test line continuation examples without spaces
AR: Michael to check on where "token" term is used in original documentation
AR: Michael to ensure language of ISS states that undefined parameter usage is
a parser error.
AR: Michael to check on current parsing of comment character placement
AR: Michael to check on status of M=
Other related posts:
- » [ibis-interconn] IBIS Interconnect Task Group Oct. 6 Minutes and Oct. 13 Agenda - Mirmak, Michael
