Re: Skill-C interface

Thanks Andrew.

I didn't know about the bitfield operators and wish I had known about them
earlier. I just tried '&', '|', and '^', and similar operations which didn't
work as intended and no one in my office knew how to do these types of
things.

The bitmap is different. It's for visualization of shapes overlaid on the
gometry. I'm working in lithography, so I would like to overlay images such
as simulation results of printed shapes over the original layout shapes in
Virtuoso. I'm also working on image/pattern matching, so I'm overlaying
approximate images with complex features (pixel accurate curves) onto the
layout. I could probably also do this by taking a screenshot of a layout and
combining that with the image in a graphics program, but then I have to do
everything by hand instead of using the power of SKILL. It works in SKILL,
it's just so slow to create a 128x128 image with 16,384 rectangles on
various layers.

Frank

"Andrew Beckett" <[EMAIL PROTECTED]> wrote in message
news:[EMAIL PROTECTED]
> Frank,
>
> On Tue, 25 Nov 2003 13:16:02 -0800, "gennari" <[EMAIL PROTECTED]>
wrote:
>
> >A few years ago I had to write a separate C++ program to get around some
of
> >the limitations of SKILL, and then call that program from SKILL. In
> >particular, SKILL/Cadence crashed when I tried to create a hash table of
> >several hundred thousand x/y points. Also, I couldn't find any way of
> >performing bit-level operations in SKILL such as bitshifts, bit masking,
> >etc. In fact I think skill uses 32 bits in all integers, even when I only
> >need to store an 8-bit value, and that's 4X memory overhead. I eventually
> >had to implement the layout database and gometry query functions into my
C++
> >program to aviod writing I/O files of many MB. Now the program is
> >independent of Cadence, but I wonder if all that work was really worth
it.
> >
>
> functions such as bor, band - which are equivalent to operators | and &.
Also
> bnand, bnor, bxor, bxnor (operators for each of these too).
> leftshift, rightshift (<< and >>).
> The bitfield, bitfield1 functions as well are useful. These are
equivalents
> of doing something like:
>
> a=1234
> a<4:2>  => 4
> a<4> => 1
> a<<1 => 2468
> a>>2 => 308
> a&10 => 2
> a|5 => 1239
> a^2 => 1232 (xor)
>
> Bet you didn't know you could do that ;-(
>
> They're all documented, and have been there for as long as I can remember.
>
> >Oh, and as a side note, is there any way to create a small bitmap image
in
> >Cadence other than building it from single pixel rectangles on the
> >multi-colored "y0" - "y9" layers in the LSW? It takes a really long time
to
> >do this in SKILL.
> >
>
> Depends what you want to use the bitmap for. If it's for menu items, icons
> etc in DFII, then hiStringToIcon and related functions would help. Some of
the
> ^dl (displayList) functions can be used too (don't get used much, but can
be
> quite handy).
>
> Andrew.
>
> >Frank
> >
> >"Andrew Beckett" <[EMAIL PROTECTED]> wrote in message
> >news:[EMAIL PROTECTED]
> >> You could use the Integrators Toolkit (ITK-DB). This allows you to
write
> >> standalone applications which access the database from C, and there is
> >some
> >> (limited) support for invoking SKILL from this.
> >>
> >> However, I suspect this is not what you want. You can't (for example)
link
> >in
> >> some C code with DFII and call that from SKILL (we don't support that,
for
> >> a variety of reasons - one being that it is rarely necessary). What you
> >can do
> >> however is to write your computationally intensive tasks in a separate
> >program,
> >> which you can then invoke using the ipc function calls (e.g.
> >ipcBeginProcess),
> >> and then communicate to that external program either synchronously or
> >> asynchronously. This can be quite an effective means of doing things
> >outside.
> >>
> >> What sort of intensive operations are you talking about? SKILL can be
> >pretty
> >> quick provided that you do things correctly (it's byte-code compiled,
> >> and runs on a virtual machine).
> >>
> >> Regards,
> >>
> >> Andrew.
> >>
> >>
> >> On Mon, 24 Nov 2003 15:20:13 -0700, sampath <[EMAIL PROTECTED]> wrote:
> >>
> >> >Hi,
> >> >is there anyway that i can mix skill and c code,
> >> >I am looking for a way to do some runtime intensive operations in c
and
> >> >get the data into a skill code?
> >> >can somebody tell a solution?
> >> >sampath
> >>
> >> --
> >> Andrew Beckett
> >> Senior Technical Leader
> >> Custom IC Solutions
> >> Cadence Design Systems Ltd
> >
>
> --
> Andrew Beckett
> Senior Technical Leader
> Custom IC Solutions
> Cadence Design Systems Ltd