Ocean Script-starting

[Zeus_ark]

Hi, I just started using OCEAN, could you suggest me tutorial or sites where I can get practice problem to get a hold on OCEAN?

 

[pavel_adameyko]

Hello
i have some expirience with ocean scripts writing - so if you have questions - ready to help.

 

[Zeus_ark]

I went through OCEAN SCRIPT pdf, I want to practice OCEAN right from beginners level.

 

[pavel_adameyko]

I went through OCEAN SCRIPT pdf, I want to practice OCEAN right from beginners level.

I advice you to begin with practical tasks - for example, write script which simulate amplifier on corners and store the results in file and so on.

 

[Zeus_ark]

Hi I tried to do a simple program to get AC, DC and transient analysis of an amplifier.
here is the code
=========================================

ocnWaveformTool( 'awd )
simulator( 'spectre )
design( "/tmp/mu92/cadence/practice1a/spectre/schematic/netlist/netlist")
resultsDir( "/tmp/mu92/cadence/practice1a/spectre/schematic" )
modelFile(
'("/home/mu/gpdk090_AnalogIC/libs.cdb/gpdk090/../../models/spectre/gpdk090.scs" "NN")
'("/home/mu/EE223/gpdk090_AnalogIC/practice2.scs" "")
)
createNetlist( ?recreateAll t)
analysis('tran ?start 0 ?stop 10m ?step 10n)
analysis('ac ?start 1 ?stop 4G ?log 10)
analysis('dc ?saveOppoint t)
desVar( "Vdc" 1.2)
desVar( "Cload" 1p)
desVar( "R" 9.37K)

temp( 27 )
run()

ocnDisplay('analysis 'tran)
selectResults('tran)

; plot(getData(?results 'tran))
; openResults("./psf" t)
; addSubwindow()
ocnDisplay('analysis 'ac)
selectResults('ac)
plot( v("Out") v("In") )

selectResults('dc)
ocnPrint( ?output "myfile" v("Out") )
===========================================
I have following doubts:
a) I get this error when I simulate the file :
Warning: wave1 is not a waveform object that can be displayed and will be turned OFF automatically
name : "v(\"in\")"
expr : "v(\"in\")"
how do I correct this.
b) In the program I want to plot transient as well as AC in the same waveform window, how do I do it? I tried doing the subwindow thing!
c) how do these functions :
ocnDisplay('analysis 'tran)
selectResults('tran)
actually work?

Please answer the questions, I am trying my best to learn on my own and any help would be very helpful

 

[pavel_adameyko]

Hello
you should do smth like that:

selectResults('ac)
plot(VF("Out"))
selectResults('tran)
addSubwindow()
plot(VT("Out"))

Regards.

 

[Zeus_ark]

Thank you Pavel

 

[Ravinder487]

These are the warnings and errors I'm getting using oceanScript.Could any body figure out the mistakes I made in the script

---------- Post added at 11:19 ---------- Previous post was at 11:10 ----------


Can any body figure out the mistakes I did in scripting

---------- Post added at 11:21 ---------- Previous post was at 11:19 ----------


Can any body figure out the mistakes I did in scripting

---------- Post added at 11:32 ---------- Previous post was at 11:21 ----------


Sorry I've attached wrong screenshot.Above are the correct screenshots.one is gmid.ocn file and the other is screen short CIW window after running load("gmid.ocn")

 

[sepidehs84]

Hi,

Do you know what the ocnPrint command is for ac analysis?

for transient analysis I used: ocnPrint(IT("/V0/Plus") ?output "/full/output/file/path.txt" ?precision 8 ?numberNotation 'none ?from 0n ?to 10n ?step 1n)and it worked.

I am wondering if there is any equivalent for ac analysis.



Thanks!

 

[Prashanthanilm]

Hello
i have some expirience with ocean scripts writing - so if you have questions - ready to help.

How to write a code for calculation the gate cap of an simple inverter?

 

[guitar_man]

Hello,

I was wondering, is it possible to write a script that interactively changes a design variable in a while loop? My idea is to measure a voltage at a node of a transistor and if it is less than a given value, change the size of the transistor. I have experience in C/C++ programming so the algorithm there would be something like
while(voltage < VALUE){
change transistor size
calculate voltage
}
I tried to implement something like that in OCEAN, but got an error:
*Error* eval: not a function - set_W_tail(W_tail_temp)
this function is my own and is given below...


the code is given below:
; initial setup stuff
ocnWaveformTool( 'wavescan )
simulator( 'spectre )
design( "/home/Cadence/cadence/simulation/Ocean_test/spectre/schematic/netlist/netlist")
resultsDir( "/home/Cadence/cadence/simulation/Ocean_test/spectre/schematic" )
modelFile(
'("/opt/ncsu-cdk/models/spectre/standalone/tsmc25N.m" "")
'("/opt/ncsu-cdk/models/spectre/standalone/tsmc25P.m" "")
)
desVar( "ibias" 10u )
desVar( "in_n" 1.25 )
desVar( "in_p" 1.25 )
desVar( "vdd" 2.5 )
desVar( "W_tail" 1u )
temp( 27 )
; function that gets the new transistor Width value. It should alter the W_tail design variable and run the calculations again
procedure( set_W_tail(W)
desVar( "W_tail" W )
run()
selectResult( 'tran )
ICMmax = evalstring(desVar("vdd")) - value(v("/net21") 1e-6) ;calculate the voltage at a transistor node when X=1us
;printf("width = %f \n" ICMmax)
ICMmax ; the value that is returned by the function
)

specICMmax = 0.1
W_tail_temp = evalstring(desVar("W_tail"))

analysis('tran ?stop "50u" )
run()
selectResult( 'tran )
measuredICMmax = evalstring(desVar("vdd")) - value(v("/net21") 1e-6)
;here I should theoretically change the width until the condition is met
while( (measuredICMmax > specICMmax) (measuredICMmax=set_W_tail(W_tail_temp) W_tail_temp=W_tail_temp+1e-6)))


So the main question would be - is it possible to change a design parameter and run a simulation (evaluate the altered parameter) in a WHILE loop? (maybe it is done using something else). All examples just use printf or something like that with while loops...