How can I create a PCell?

[Reotaro Hashemoto]

Hi,
I want to know the specific steps to create basic SKILL pcell that
should be part in a PDK.. Are CDF and callbacks part of pcell?
Finally, I want to know what are the specific skill files that
represents the pcell in case I want to see some?

Thanks in advance

 

[Guenther Sohler]

A simplce pcell code looks like


pcDefinePCell(list(ddGetObj("testlib") "pcell" "layout")
(
(width 1.0)
)
dbCreateRect(pcCellView,"M1" list(0:0 width:width))
t
)

save it as a file .il, and change the paramaters in the file.
once you load the file, the pcell is created

cdf paramaters are not part of the pcells, but they interact with the
pcell parameters.
if there are no cdf paramaters definded. the pcell parameters take
precedance. if there are cdf, they take precedence. cdf parameters should
match with pcell paramaters when present.

For having a pcell, you just need to take care of the pcell source code.
(at a first step).
You cannot yet define extra functions in your pcell code.



On Sun, 18 Nov 2007 03:02:52 -0800, Reotaro Hashemoto wrote:

Hi,
I want to know the specific steps to create basic SKILL pcell that
should be part in a PDK.. Are CDF and callbacks part of pcell?
Finally, I want to know what are the specific skill files that
represents the pcell in case I want to see some?

Thanks in advance

 

[Andrew Beckett]

On Mon, 19 Nov 2007 12:25:11 +0100, Guenther Sohler <guenther.sohler@wipro.com>
wrote:

A simplce pcell code looks like


pcDefinePCell(list(ddGetObj("testlib") "pcell" "layout")
(
(width 1.0)
)
dbCreateRect(pcCellView,"M1" list(0:0 width:width))
t
)

save it as a file .il, and change the paramaters in the file.
once you load the file, the pcell is created

cdf paramaters are not part of the pcells, but they interact with the
pcell parameters.
if there are no cdf paramaters definded. the pcell parameters take
precedance. if there are cdf, they take precedence. cdf parameters should
match with pcell paramaters when present.

For having a pcell, you just need to take care of the pcell source code.
(at a first step).
You cannot yet define extra functions in your pcell code.

Actually you can reference user defined functions within your pcell code - you
just need to ensure that those functions always get loaded - so any user-defined
functions you reference within a pcell should be loaded from the libInit.il file
of the library containing the pcells. It's not necessary (and in fact you
shouldn't do this) to load the code defining the pcDefinePCell from the
libInit.il - the code within the pcDefinePCell gets stored in the cellView
itself.

Before getting into the area of CDF callbacks, please read my solution on
sourcelink.cadence.com "The Dangers of CDF Callbacks" - to make sure you don't
fall into bad habits at the beginning!

Regards,

Andrew.
--
Andrew Beckett
Senior Solution Architect
Cadence Design Systems, UK.