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Simulators >> Circuit Simulators >> BRIEF, NXX Statement in Hspice
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Message started by qiushidaren on Feb 5^th, 2007, 12:55am

Title: BRIEF, NXX Statement in Hspice
Post by qiushidaren on Feb 5^th, 2007, 12:55am

Hi all,

I am studying Hspice right now. In Hspice manual it says like this:
BRIEF, NXX: Stops printback of the data file, until Hspice finds an .OPTION BRIEF=0, or the .END statement. It also resets the LIST, NODE, and OPTS options, and sets NOMOD. BRIEF=0 enables printback. NXX is the same as BRIEF.

But I still can't understand this kind of explanation, what does "printback of the data file" mean here, and what's NXX? Thank you in advance!

Regards,
Terry

Title: Re: BRIEF, NXX Statement in Hspice
Post by Geoffrey_Coram on Feb 5^th, 2007, 5:32am

When you run HSpice, it usually echoes the entire input file -- and included libraries! -- to stdout, or to the log file. Often, you don't care to see the libraries spewed to the screen. The manual is saying you can:

.OPTION BRIEF

or

.OPTION NXX

and get the same behavior (suppress echoing).

Title: Re: BRIEF, NXX Statement in Hspice
Post by qiushidaren on Feb 5^th, 2007, 6:10am

Geoffrey_Coram wrote on Feb 5^th, 2007, 5:32am:

Hi Geoffrey, do you know what does NXX stand for here, BRIEF means brief, but how about NXX, I really can't guess out where do these acronyms come from.

Title: Re: BRIEF, NXX Statement in Hspice
Post by Geoffrey_Coram on Feb 5^th, 2007, 2:08pm

qiushidaren wrote on Feb 5^th, 2007, 6:10am:

Hi Geoffrey, do you know what does NXX stand for here, BRIEF means brief, but how about NXX, I really can't guess out where do these acronyms come from.

No idea. Could be from some obsolete simulator, lost to history ... In HSpice, some of the device aspects (cgs, gm, gds) are also known by odd names like LX20.

Title: Re: BRIEF, NXX Statement in Hspice
Post by qiushidaren on Feb 5^th, 2007, 5:18pm

Geoffrey_Coram wrote on Feb 5^th, 2007, 2:08pm:

qiushidaren wrote on Feb 5^th, 2007, 6:10am:

Hi Geoffrey, do you know what does NXX stand for here, BRIEF means brief, but how about NXX, I really can't guess out where do these acronyms come from.

No idea. Could be from some obsolete simulator, lost to history ... In HSpice, some of the device aspects (cgs, gm, gds) are also known by odd names like LX20.

Got it, thank you.

-Terry

Title: Re: BRIEF, NXX Statement in Hspice
Post by OldHouseBlues on Feb 8^th, 2007, 6:24am

Geoffrey_Coram wrote on Feb 5^th, 2007, 2:08pm:

qiushidaren wrote on Feb 5^th, 2007, 6:10am:

Hi Geoffrey, do you know what does NXX stand for here, BRIEF means brief, but how about NXX, I really can't guess out where do these acronyms come from.

No idea. Could be from some obsolete simulator, lost to history ... In HSpice, some of the device aspects (cgs, gm, gds) are also known by odd names like LX20.

Regarding the "odd names like LX20", this is an HSPICE feature described as "element
template output" in the HSPICE Simulation and Analysis User Guide. It allows the user to:

"...output user-input parameters, state variables, stored charges, capacitor currents,
capacitances, and derivatives of variables."

Title: Re: BRIEF, NXX Statement in Hspice
Post by Geoffrey_Coram on Feb 8^th, 2007, 11:20am

OldHouseBlues wrote on Feb 8^th, 2007, 6:24am:

Regarding the "odd names like LX20", this is an HSPICE feature described as "element template output" in the HSPICE Simulation and Analysis User Guide.

But why LX20? How on earth is a designer supposed to remember that LX20 is Cgs not Cgd or gm? Hmm, let's see, the top 20 things I'm likely to want to know about my device are: id, is, ig, ib, ... qd, ... dang, do the q's come before or after the c's?

Title: Re: BRIEF, NXX Statement in Hspice
Post by John O Donovan on Feb 8^th, 2007, 2:31pm

I think that the LX/LV numbers are from the layout of the instance data structures in SPICE2. The number was the index into an array I think (or something similar).

Regards,
John

Title: Re: BRIEF, NXX Statement in Hspice
Post by Andrew Beckett on Feb 8^th, 2007, 6:56pm

Geoffrey,

You don't have to use the obscure, hard to remember, element numbers in HSPICE these days. You can just do:

Code:

.PROBE CGSBO(M1)

Rather than LX20. Each of the element templates has an equivalent meaningful name.

Regards,

Andrew.

Title: Re: BRIEF, NXX Statement in Hspice
Post by Geoffrey_Coram on Feb 9^th, 2007, 6:29am

Andrew Beckett wrote on Feb 8^th, 2007, 6:56pm:

You don't have to use the obscure, hard to remember, element numbers in HSPICE these days

I know; this sub-thread got started with "what does NXX mean?"

I wonder if LX20 originated from the Spice2 Fortran code ... I don't recall seeing it in Spice3's C code.