Looking CalTech Interchange Format Syntax.

Hi all,

Does CalTech Interchange Format (CIF) has BNF on the Internet? If so,
could someone give me the link, please? Thanks.

HS Phuah

 

You're working with CIF as well as GDSII? There are many websites with
info on both CIF and GDSII, such as:
http://www.wrcad.com/manual/xicmanual/node476.html
http://www.rulabinsky.com/cavd/text/chapb.html

I can't find a site with BNF for CIF at the moment. I
think CIF actually stands for "CalTech Intermediate Format", so you
might have an easier time Google searching with that term. CIF is a little
tricky since there are many optional parameters, custom languange
extensions, etc. For example, you can have an entire layout in a CIf
text file with no newlines or whitespace and only refer to the commands
by their first letters (if unique). It's less well-defined than GDSII,
though easier to work with since it's text.

Frank

 

I was able to find the following:
http://www.ee.vt.edu/~ee5545jg/ee5545e/sld004.htm

Otherwise, I'd imagine it's documented in Mead & Conway; see if a
coworker/professor who has been around awhile has a copy.

If I may ask, what's the interest in CIF? I haven't played with it
since I used the Chipmunk tools and LEdit back at Caltech. (Though, by
the time I got there, the actual Chipmunk cluster was long gone, and we
were running on 300s or 400s...)

 

I am requested to write a program to convert GDSII to CIF and vice
versa for layout automation software. That's why I am looking for CIF
BNF.

HS Phuah

 

According to the Cadence Sourcelink, you are right. CIF stands for
CalTech Intermediate Format. I found the websites prior to posting my
question. Unfortunately, those information could not help me to much to
start my project.

 

This is a solved problem. Is there a reason why pipo doesn't work for
you? Pull up the .../tools/doc/transref/transref.pdf documentation in
Acrobat for information on this.

If you're doing this as a learning exercise, that's great. But if it's
to write a competing tool, we can't exactly help you in this regard.

 

Ok, I managed to track down a copy of Mead & Conway (which is out of
print). I'm reproducing the CIF 2.0 grammar found on pages 116-117 here
(and translating it to BNF on the fly) in the hopes that it becomes part
of Google's collective memory.

cifFile ::= (blank* command? semi)* endCommand blank*
command ::= primCommand | defDeleteCommand |
defStartCommand semi (blank* primCommand? semi)* defFinishCommand
primCommand ::= polygonCommand | boxCommand | roundFlashCommand |
wireCommand | layerCommand | callCommand | userExtensionCommand |
commentCommand
polygonCommand ::= "P" path
boxCommand ::= "B" integer sep integer sep point (sep point)?
roundFlashCommand ::= "R" integer sep point
wireCommand ::= "W" integer sep path
layerCommand ::= "L" blank* shortname
defStartCommand ::= "D" blank* "S" integer (sep integer sep integer)?
defFinishCommand ::= "D" blank* "F"
defDeleteCommand ::= "D" blank* "D" integer
callCommand ::= "C" integer transformation
userExtensionCommand ::= digit userText
commentCommand ::= "(" commentText ")"
endCommand ::= "E"
transformation ::= (blank* ("T" point |
"M" blank* "X" |
"M" blank* "Y" |
"R" point)*)*
path ::= point (sep point)*
point ::= sInteger sep sInteger
sInteger ::= sep* "-"? integerD
integer ::= sep* integerD
integerD ::= digit+
shortname ::= c c? c? c?
c ::= digit | upperChar
userText ::= userChar*
commentText ::= commentChar* |
commentText "(" commentText ")" commentText
semi ::= blank* ";" blank*
sep ::= upperChar | blank
digit ::= "0" | "1" | ... | "9"
upperChar ::= "A" | "B" | ... | "Z"
blank ::= any ASCII character except digit, upperChar, "-", "(", ")",
or ";"
userChar ::= any ASCII character except ";"
commentChar ::= any ASCII character except "(" or ")"

 

That's quite a project if you plan to support the complete CIF/GDSII
formats. Some of the shapes in one format can't easily be represented in
the other (round flashes in GDSII?). If you want a reliable converter that
others will be using then you probably want to look for a cheap/free
conversion tool, or use Cadence. What is the intended use of your tool?
What sort of design flow involves both CIF and GDSII?

Frank

 

Thank you for the information. We know CIF/GDSII conversion tools are
available in the market. Unfortunately, some of them cannot integrate
into our design flow environment. In my company, we use many EDA tools
from different vendors. All EDA tools have been customized to suit our
design flow environment here.

In my layout automation team, we have only 3 engineers customized
layout automation tools. To make the matter worse, all of us have
different education and working experience. None of us knows have solid
understand about GDSII and CIF formats. My project leader thought it
was easy to implement it. I only knew the difficulty after I read
through the CNF slides yesterday.

Anyway, I am really appreciated all your helps. I had learned a lot
from the GDSII and it is good for me to understand how software
developers handle shapes, graphics and etc in binary files.

 

On a similar note ...

does anyone have a set of C ( or C++ or some classLibrary ) of functions
to read/write GDSII. (version 6 or 5 or ... )

At my last job a co-worker had created a compliant GDSII reader/writer
in C. This was very useful in many of our custom tools. As time went on,
our company evolved into using comercial tools and this was only used
when the commercial tools had problems ( i.e. hidden 2Gig limit or
internal cell size limits, strange illegal cell names ... ) and custom
debugging
was needed.

-- Gerry @ www.ictooling.com

(still remembering the "good-old-days" when you had to write your own tools
and GDSI was the latest fad ... )

 

I tried to get Softjin's ANUVAD a few months ago. I filled out their
request form and never got anything. Eventually they called me about it
and seemed helpful, but by that time I didn't need it anymore. It seems
like ANUVAD is the right way to go, especially if you plan to work with
OASIS sometime in the near future. I'm not sure if their free source
GDSII/OASIS tools are really free for commercial purposes. I'm planning to
look into their tools in more detail later when I need the OASIS
converter so I guess I'll find out.

Frank

 

It sounds like ANUVAD is a good way to go when it's time to add OASIS
support to my company's tools (unless you're a Softjin marketer in
disgise. I guess back at the beginning of the year when I tried to get
the tool the registration system wasn't fully functional. I'll certainly
have to take a look in the near future.

My layout viewer isn't open source (though I did consider that option). I
would like to make it available to others, but I don't exactly own the
copyright as it was initially developed under a research grant at UC
Berkeley. Maybe I can publish some of the algorithms and ideas involved in
that project in a future paper, but I don't think I can release it as open
source.

Frank

 

Frank,

I gave it a quick look. So far
The registration works fine. The code compiles nicely on solaris and
linux, even if there are some strangeties in the makefiles. I tried the
programs on a few stream files (below 2GB), and it ran without trouble.
The license allows commercial use, unreleased enhancements, and binary
distribution. The directory layout is very clear and clearly mapped to
libraries and namespaces. Both the design and the library usage are
concisely and accurately documented. Only good surprises so far.

Is your openGL layout rendering code now open sourced ?

 

Try this one : StreamVista : http://www.semigy.com/
A free GDSII viewer. (running Windows only)

The speed is good, with nice features including zooming, ruler, etc ...

================
Kholdoun TORKI
http://cmp.imag.fr
================