Ocean Scripts

Tao-Yi Lee

Advisor: Dr. Yu-Jiu Wang

RFVLSI LAB, NCTU

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Ocean Scripts

• OCEAN lets you set up, simulate, and analyze

circuit data. OCEAN is a text-based process that

you can run from a UNIX shell or from the

Command Interpreter Window (CIW).

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What can Ocean Scripts do?

• Create scripts that you can run repeatedly to verify

circuit performance

• Run longer analyses such as parametric analyses

and statistical analyses more effectively

• Run long simulations in OCEAN without starting the

Virtuoso® Analog Design Environment graphical

user interface

• Run simulations from a nongraphic, remote terminal

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Using OCEAN from a UNIX Shell

• Interactive

• Non Interactive

Unix $ ocean

ocean>

Unix $ ocean -nograph <

oceanScript.ocn > oceanScript.log

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Scaling Factors

Character Name Multiplier Examples

Y Yotta 1024 10Y [ 10e+25 ]

Z Zetta 1021 10Z [ 10e+22 ]

E Exa 1018 10E [ 10e+19 ]

P Peta 1015 10P [ 10e+16 ]

T Tera 1012 10T [ 1.0e13 ]

G Giga 109 10G [ 10,000,000,000 ]

M Mega 106 10M [ 10,000,000 ]

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Scaling FactorsCharacter Name Multiplier Examples

K Kilo 103 10K [ 10,000 ]

% percent 10-2 5% [ 0.05 ]

m milli 10-3 5m [ 5.0e-3 ]

u micro 10-6 1.2u [ 1.2e-6 ]

n nano 10-9 1.2n [ 1.2e-9 ]

p pico 10-12 1.2p [ 1.2e-12 ]

f femto 10-15 1.2f [ 1.2e-15 ]

a atto 10-18 1.2a [ 1.2e-18 ]

z zepto 10-21 1.2z [ 1.2e-21 ]

y yocto 10-24 1.2y [ 1.2e-24 ]2014/4/18 Ocean Scripts 6

Comments

• SKILL permits two different styles of comments– Block oriented: comments are delimited by /* and */

– Line-oriented where the semicolon (;) indicates that the rest of the input line is a comment.

/* This is a block of (C style) comments

comment line 2

comment line 3 etc.

*/

x = 1 ; comment following a statement

; comment line 1

; comment line 2 and so forth

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Arrays

• You must explicitly create arrays before using them so

the necessary storage can be allocated

• Arrays are not typed. Elements can be different types.

• Arrays are one dimensionaldeclare( week[7] ) ;=> array[7]:9780700

week ;=> array[7]:9780700

type( week ) ;=> array

days = ’(monday tuesday Wednesday)

for(day 0 length(week)-1

week[day] = nth(day days)

)

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Simulation Commands: resultsDir()

• resultsDir( t_dirName ) => undefined/nil

• Specifies the directory where the PSF files (results)

are stored. If you do not specify a directory with this

command, the PSF files are placed in ../psf to the

netlist directory.

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Simulation Commands: simulator()

• simulator( s_simulator ) => s_simulator/nil

• Starts an OCEAN session and sets the simulator name for that session. The previous session (if any) is closed and all session information is cleared.

• Possible values:

– Spectre

– spectreVerilog

– aps

– ultrasim

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Simulation Commands: design()

• design( t_cktFile | t_lib t_cell t_view [t_mode]) => t_cktFile/nil | (t_lib t_cell t_view)/nil

• Specifies the name of the design to be simulated. For the lib, cell, view version of the design command, you can specify the mode (r, w or a, representing read, write or append) in which the design should be opened

• Example:

– design("mylib" "ampTest" "schematic" “r")

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Simulation Commands: createNetlist()

• createNetlist( [?recreateAll b_recreateAll] [?display

b_display] ) => t_filename/nil

• Creates the simulator input file.

• If the design is specified as lib/cell/view, this

command netlists the design, if required, and

creates the simulator input file.

• If the design is specified as netlist file, that netlist is

included in the simulator input file.

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Simulation Commands: modelFile()

• modelFile( [g_modelFile1 [g_modelFile2 …]] ) =>

l_modelFile

• Example:

– modelFile( '("/home/PDKs/OA65_LIB/tsmcN65/../models

/spectre/crn65gplus_2d5_lk_v1d0.scs" "tt_bip"))

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Simulation Commands: analysis()

• analysis( s_analysisType [?analysisOption1

g_analysisOptionValue1]… [?analysisOptionN

g_analysisOptionValueN]) => undefined/nil

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Example: DC and TRAN simulations

simulator( 'aps )

design( "N65_TY" "tb_TX" "config" "r")

createNetlist( ?recreateAll t ?display t)

createFinalNetlist()

resultsDir("/home/michael/OA65/tb_TX_ocn")

modelFile(

'("/<path_to_model>/tsmcN65/../models/spectre/crn65gplus.scs" "tt")

'("/<path_to_model>/tsmcN65/../models/spectre/crn65gplus.scs" "tt_dio")

...

...

)

analysis('dc ?saveOppoint t )

analysis('tran ?stop "50n" ?step 0.016n ?errpreset "moderate" )

store('tran "./tranStoreFile" )

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Example: PSS and Load-Pull simulations

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References

• Cadence, “OCEAN Reference”, Product Version

6.1.4, March 2010

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