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Problem running very basic LVS

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lagos.jl

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ivpcell cadence

Hello all; it's me again begging for some help! :D

I am trying to learn how to do LVS by following the "Cell Design
Tutorial" on the Cadence documentation, which uses a very simple 2-
input mux as example. Everything went fine up to the DRC, but I
started having trouble on the LVS phase. The LVS failed with the
following errors (si.log):
...
Begin netlist: Nov 7 03:59:41 2007
view name list = ("auLvs" "extracted" "schematic")
stop name list = ("auLvs")
library name = "tutorial"
cell name = "mux2"
view name = "extracted"
globals lib = "basic"
Running Artist Flat Netlisting ...
*WARNING* invalid cell view -- 0(unknown)
*WARNING* invalid cell view -- 0(unknown)
global error:
Cannot find switch master cell for instance +13 in cellView (mux2
extracted) from viewlist 'auLvs extracted schematic ' in library
'tutorial'.
...(same error repeated for every mos instance in the extracted
view)...

Research on the web lead me to think that this was due to netlisting
errors. When I look at the properties of the transistors in the
extracted view, they all are "ivpcell" views and not "auLvs". Despite
I don't yet understand view lists, I tried creating a .simrc file with
the following contents:

lvsLayoutViewList = '("ivpcell" "auLvs" "extracted" "schematic")
lvsLayoutStopList = '("ivpcell" "auLvs")
lvsSchematicViewList = '("auLvs" "schematic")
lvsSchematicStopList = '("auLvs")
lvsLayoutVersionName = nil
lvsSchematicVersionName = nil

Now the "invalid cell view" warnings are gone, but then the LVS fails
with other errors:

Begin netlist: Nov 7 04:12:16 2007
view name list = ("ivpcell" "auLvs" "extracted" "schematic")
stop name list = ("ivpcell" "auLvs")
library name = "tutorial"
cell name = "mux2"
view name = "extracted"
globals lib = "basic"
Running Artist Flat Netlisting ...

*Error* Cell: pfet in library: sample is missing a simInfo section
in it's CDF for the current simulator.
*Error* artIsCallablep: argument #1 should be either a string or a
symbol (type template = "S") - nil
error in instance path /+13:
Error in evaluating property value: 'ancNetlistFileInstOutput()'.
...(same error repeated for all pmos instances)...

*Error* Cell: nfet in library: sample is missing a simInfo section
in it's CDF for the current simulator.
*Error* artIsCallablep: argument #1 should be either a string or a
symbol (type template = "S") - nil
error in instance path /+6:
Error in evaluating property value: 'ancNetlistFileInstOutput()'.
...(same error repeated for all nmos instances)...

One last weird observation. All the instances in the extracted view
belong to library named "sample", and not to the "pCells" library, as
(I guess) one would expect. Transistor cells in the the "sample" lib
don't have 'auLvs' views, while the ones in the "pCells" lib have both
'auLvs' and 'ivpcell' views. ...Clueless about which one is the
correct one nor what are the differences between these two types of
views... *sigh*

It seems I am missing some basic configuration. BTW, I already checked
the 'CDS_Netlisting_Mode' is (properly?) set to 'Analog'. Any ideas on
what could be the problem? Thanks in advance for any help, and sorry
for the repeatedly long posts.

Regards,
 

ivpcell

Which tool did you use to do the LVS check?
Is it assura or diva?
The view of a cell is just a representation of the cell. It provides the necessary infomation for some tools.
It seems that your PDK is not complete. Please get a complete PDK and try again.
Cadence provides a generic 0.18um and 90nm process PDK. It supports all cadence design flow. You use it to learn the design flow.
 

type template = lvs fails

As you said, you set CDS_Netlisting_Mode to Analog, therefore LVS failed. unset CDS_Netlisting_Mode, then try again.
 

    lagos.jl

    Points: 2
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cds_netlisting_mode

Way to go, meitolake!

Either by setting "CDS_Netlisting_Mode" to "Digital" or by not setting it at all, the LVS went like breeze! :D

...I still largely ignore the subtleties between these two netlisting modes (or should I say three modes, counting the unset mode as a third option?), and I recall to have always set CDS_Netlisting_Mode to Analog up to this day; maybe I should post a new entry asking for some straight-to-the-fact explanations on this topic. :)

Thanks once again for your help.

Regards,

Jorge.
 

cds_netlisting_mode lvs

Yes, CDS_Netlisting_Mode can be set to three modes: Analog, Digital and Compatibility.
 

assura lvs flat cell

Resurecting an ancient thread...

I'm having the very same problem. Unfortunately I tried setenv'ing CDS_Netlisting_Mode to all values of {Analog, Digitail, Compatibility} and unsetenv'ing it with no luck.

Any other thoughts? If I don't get past this, soon my peers will begin to taunt me, my self esteem will drop, I will loose my professional position, become destitute, wife will kick me out, live in a cardboard box under a freeway overpass, no longer face the stresses of a hitek life & become spiritually free, start drinking the very cheapest wine with gusto... Cheers! /jd

Added after 25 minutes:


BTW, I'm using CDS_Netlisting_Mode as an environment variable, as described in the Diva manual:

setenv CDS_Netlisting_Mode Digital

The above comments mention using the set syntax, which I also tried:

set CDS_Netlisting_Mode=Digital

Neither method helped. thnx!/jd
 

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