Re: Skill-C interface

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.

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.

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