* gnucap:user

gnucap:user:alias

1.ALIAS Purpose:Creates an alias for command Status:Implemented Syntax: alias [word] [command] Comments: Command creates an alias for command with the name word. Example: gnucap>alias info sysinfo gnucap>info Model name : Intel(R) Core(TM) i5-2450M CPU @ 2.50GHz OS Description :"Ubuntu 12.04 LTS" CPU MHz : 2494.409 RAM Available :1012348kB RAM Free :132372kB gnucap>

gnucap:user:alter

13.ALTER Purpose:Command is used to change the value of a parameter. Status:Implemented Syntax: alter alter parameter-name value Comments:Sets the value of specified parameter Example: To modify the value of vcc in a ciruit gnucap>alter vcc = 15 gnucap> and to modify the resitances say R1 and R2

gnucap:user:another_page

not another page

gnucap:user:asco_for_gnucap

Why Asco? Asco is a small C program that implements several numerical optimizers and interfaces to some circuit simulators. asco (version 0.4.8) does not particularly support gnucap as a backend, but rather provides a generic interface to any program that processes text somehow.

gnucap:user:aspice

23.ASPICE Purpose:Start an asynchronous run and loads the data to specified output file. Status:Implemented Syntax: aspice input_file output_file Comments: input_file is a file which is to be run in batch mode and output_file corresponds to the file on which data will be loaded.If output_file already exists then the contents of the file are overwritten by the current output.

gnucap:user:build_system_for_plugins

compling/installing/loading plugins must be as easy as possible. there are three kinds of modules that need to taken into account. * Plugins shipped and installed within gnucap * Device models, compiled locally, simulation based * Plugins from other sources, compiled out-of-tree, installable.

gnucap:user:circbyline

21.CIRCBYLINE Purpose:Enter a circuit line by line. Status:Done

gnucap:user:cls

CLS Purpose:Clears the gnucap interpreter Status:Implemented Syntax: cls cls [command] Comments: A command can be issued with cls,it first clears the interpreter and then run th command. A bare cls simply clears the interpreter. Example: Following command first clears the screen and then runs the command 'sysinfo'.

gnucap:user:code-related_stuff

Code related stuff Currently noise simulation is implemented as plugin which is available at github at the following link It re-uses s_ac.cc file (ac simulation) to implement noise analysis. At the present moment (April 2011) noise works with only gnucap-a branch of gnucap, but hopefully soon it will work with main trunk too.

gnucap:user:colon_command

20. : Command Purpose: command : issued with multiple commands separated by semi-colon runs each command one by one. Status:Implemented Syntax: : command_1;command_2;.....;command_n Comments: Any number of commands may be passes to the : command. Shell commands passed with ! command are not executed.Like, :!ls will fail to run.

gnucap:user:colon_commmand

gnucap:user:command

gnucap:user:command_plugins

Gnucap commands are implemented as plugins. This section describes the commands supplied in the ry-1 branch in the gnucap repo (TODO: move to plugin repo). "Data" commands * MDUMP - Prints the dc tran matrix values. * RMCIRC - Removes the current circuit from the list of circuits sourced into gnucap.

gnucap:user:control_statements

Following set of control statements provides users the flexibility to write the complex scripts in Gnucap and control the execution sequence with much ease. TODO: find/reference these plugins. if else statement repeat statement while statement dowhile statement

gnucap:user:def

2.DEF Purpose:Command is used to define a function. Status:Implemented Syntax: def [function_name] Comments: Maximum three arguments can be provided which can be of type int or float.Variables are named x,y,z by default and only these variables should be used in the expression.

gnucap:user:details_of_geda_plugin

Introduction The plugin for parsing and printing schematic files in the gEDA/gschem format is at [1] Github branch. Get it by cloning the git repo : git clone git@github.sksavant/gnucap.git --branch lang_gschem or get this zip file : zipfile If you already have latest snapshot of gnucap installed you just need to get the following files: 'src/lang_gschem.cc', 'src/d_net.cc', 'src/d_place.cc'. Also some change is need in lang_verilog.cc to print verilog code correctly. Some examples are pre…

gnucap:user:discussions

is there a need for s_noise.cc? noise seems to be just about probes. in e_aux.h a function like inline COMPLEX port_noise(const node_t& n1, const node_t& n2){ std::fill_n(CKT_BASE::_sim->_sens, 1*CKT_BASE::_sim->_total_nodes+1, 0); CKT_BASE::_sim->_sens[n1.m_()] = 1; CKT_BASE::_sim->_sens[n2.m_()] = -1; CKT_BASE::_sim->_acx.fbsubt(CKT_BASE::_sim->_sens); // use Gennadys transposed fbsub double a = CARD_LIST::card_list.do_noise(); return a; }

gnucap:user:dowhile_statement

dowhile statement Purpose: dowhile statement is similar to while loop except the condition is tested after the statements are executed. Status: Done. Nesting is not supported at the moment. Syntax: dowhile condition ... end Let's see some example of dowhile statement

gnucap:user:echo

3.ECHO Purpose:Prints the text Status:Implemented Syntax: echo [text] Comments: Command echoes the text in the interpreter. Example: gnucap> echo Usage: echo [text] gnucap>echo "Hello" "Hello" gnucap>echo Hello World! Hello World! gnucap>

gnucap:user:foreach_statement

foreach statement Purpose: The statements are executed once for each value of var which ranges from m to n(including m and n) as specified by the user.The value of var can be accessed within the body of the loop by using $var. Status: Done. Nesting is not supported at the moment.

gnucap:user:gnucap_library

libgnucap is no longer experimental.

gnucap:user:gnucap_linear_solver

GNucap Linear Solver Gnucal linear solver is implemented in file m_matrix.h - that is C++ template. Most things are depicted in very extensive comments to this file. Some things which are discovered and are listed here. No zero diagonal element allowed Solver has an issue if diagonal element is zero. lets consider system:

gnucap:user:gnucap_nonlinear_solver

Gnucap Nonlinear Solver This sections will describe my (gserdyuk) analysis of gnucap nonlinear solver, comparison of it to classic Newton notation and notes which will appear on the course of the study. Classic Newton Notation Let us consider vector system of equations

gnucap:user:gnucap_python

source code at . 0.0.5 relased May 2020. A bidirectional python<->gnucap interface * based on SWIG, that * implements a Python interface for Gnucap * enables Gnucap extensions (components, algorithms..) in Python.

gnucap:user:gnucap_verilog_reconciled

== Specs, Standards The verilog-ams specification adds on to the verilog, (IEEE-1364-2001 or IEEE-1364-2005), versions. I will be testing cross workability with Icarus Verilog of the same spec year. I'm not sure yet which verilog-ams version we will use to match up with netlist verilog, and not sure about needing to read the IEEE verilog specs -- they're not freely available. Acellera.org free publishes Verilog-AMS Language Reference Manual, Release 2.3.1 last changed June 1, 2009.

gnucap:user:graphical_output_display_plugin

Purpose For displaying and analyzing output of simulation graphically in a separate window. Syntax gplot mode points gplot mode points parameters Status Currently you can plot the stored probe data by choosing corresponding mode and points. You can customize the plot by setting proper options or by providing appropriate parameters.

gnucap:user:history

4.HISTORY Purpose:Review the previous commands Status:Implemented Syntax: history history -t history -s Comments: Command prints the history of commands that has been executed after enabling the history track mode. Commands tracking can be stopped by disabling the history mode.

gnucap:user:if_else_statement

if statement Purpose: This statement is used to make one-time decisions,i.e,to execute some part of the script and ignore other. Status: Done Syntax: if condition ... elif another_condition ... end Following examples illustrates the use of if statements in Gnucap.

gnucap:user:ir_filters_and_tr-_noise

the gnucap bm_ framework can be used to plug in impulse response filters to elements. with these, filtering is as simple as this: spice .model sfir fir coefs=(1,0,-1,1,1,1,1,0,0,-1) step=1m .model sir int_filter step=0.1m v1 nin 0 1 e1 nout 0 nin 0 sfir e2 nint 0 nin 0 sir.print tran v(nin) v(nint) v(nout) Vout(e1) .tran 0 2m 0.02m basic .end here sfir is a finite impulse reponse filter with 10 coefficients. sir is an integrating filter, which is implemented similarly to the other iirs (but more…

gnucap:user:istring

case sensitivity in maps gnucap provides a flag for case sensitivity that affects the parsing and interpretation of identifiers. It is user controlled. The main use case is the support for mostly obsolete but still widely used input languages such as SPICE. the case sensitivity flag affects declaration and lookup.

gnucap:user:language_plugin_for_gschem

Language Plugin for schematic files of GSchem Introduction The plan [1] is to write a plugin for Gnucap to support schematic files from gEDA/gschem [2]. Schematics are graphical representation of circuits using abstract symbols showing components and their connections. The idea for netlist import and export is at the wiki page : Netlist import and export The technical details on on how this gEDA/gschem plugin is implemented is at the page: Details of gEDA plugin

gnucap:user:language_plugin_for_qucs

Language plugin for Qucs (see for an implementation) The basic idea is to parse a qucs schematic or a qucsator netlist. gnucsator qucsator is the default simulation engine behind the qucs user interface. it does dc/ac/tran and sparam analysis, and maybe a (simplified, linear?) kind of harmonic balance.

gnucap:user:mdump

5.MDUMP Purpose:Prints the dc tran matrix values. Status:Implemented Syntax: mdump mdump filename Comments: Command dumps the dc-tran matrix into the console,if the filename is specified then output is redirected to the file.Two matrices one before the lu decomposition and one after the lu decomposition is dumped.

gnucap:user:netlist_import_and_export

We need a universal translator system that can translate in all directions between Free EDA tools, possible future free EDA tools, and outside tools that are likely to be used with free EDA tools. Most existing EDA tools, both free and commercial, do not permit or implement export functionality needed to access user data, needlessly or intentionally locking in users.

gnucap:user:newtonnumericexample1

Newton Numeric Example 1 Let us consider simple 1-node circuit --------+------------- | | | I=0.001 R=1000 i=V^3/1000 | | | --- --- ---

gnucap:user:noise_calculation_basics

Noise calculations basics Noise is claculated using adjacent system method [TBD GS - complete, explain ]

gnucap:user:noise_implementation

Noise Implementation This section contains all stuff related to AC Noise calculation in Gnucap. Status Noise models and noise analysis are implemented in modelgen-verilog. See for example tests/v_noise.2.gc. The implementation makes use of Verilog-A noise functions in the device models and noise probes that measure the noise level at the node connected to it. Noise analysis is performed during AC analysis.

gnucap:user:noise_syntax

Noise Simulation Syntax To run noise simulation - ad the following line to circuit file (spice format): .noise V(a,b) Dev stepmode points fromF toF * V(a,b) - output to measure noise at - nodes a to b; possible form: V(a) is the same as V(a,0)

gnucap:user:one_more

test

gnucap:user:pre

6.PRE Purpose:Executes command prior to parsing the circuit Status:Not implemented

gnucap:user:programingdetails

Programming Details Topmost level solver computations are concentrated in s__solve.cc file in SIM::solve(...) inside it main important steps: do { assume we have some value of unknowns: X_c calculate model parameters evaluate models; load matrices (Jacobian J and vector FG)

gnucap:user:queuesandoptbypass

Queues and OPT::bypass To improve speed GNucap solver uses device queues, most queues are activated when OPT::bypass is set to true. This section will create analysis of how this is implemented. No bypass (OPT::bypass==false) Looking at code of SIM::evaluate_models() - if (OPT::bypass==false) then only _late_evalq queue is used.

gnucap:user:quit

7.QUIT Purpose:Terminates the gnucap interpreter Status:Implemeted Syntax: quit quit [status] Comments: This quit command is the modified form of the current quit command.status(integer)can be passed as a parameter which signals the success or failure of the termination process to the Operating System.Non-zero status indicates unsuccessful termination to the Operating System.

gnucap:user:repeat_statement

repeat statement Purpose: This command executes the statements defined within its body “n” number of times where n is the number passed by the user.If no number is passed,loop is executed infinite number of times. Status: Done.Nesting of loops is not supported at the moment.

gnucap:user:reset

9.RESET Purpose:Reset command re-parses the input file.The circuit can then be re-run from its initial state Status:Not implemented

gnucap:user:rmcirc

8.RMCIRC Purpose:Removes the current circuit from the list of circuits sourced into gnucap Status:Done

gnucap:user:run

RUN Purpose:Run the silumation as specified in the input file. Status:Done

gnucap:user:schematic_geometry

moved.

gnucap:user:sensitivity_command

Overview Sensitivity can be calculated from a solution of the adjoint system, see “Computer Methods for Circuit Analysis and Design (Vlach and Singhal)”. Essentially, an (infinitesimal) change in a parameter p can be thought as a (infinitesimal) current injected into the network. an observable can be thought as a function f of the voltage vector v. if f is linear, then, ignoring the offset, it can be written as a scalar product s=< F, v >== with some vector F. but then df/d…

gnucap:user:set

10.SETV Purpose:Sets the value of a variable Status:Implemented Syntax: setv assign_to = value setv assign_to value Comments: Commands sets the value of “assign_to” variable to “value”.These values can be accessed via a show command.

gnucap:user:setv

gnucap:user:shell

11.SHELL Purpose:Calls the command interpreter of operating system. Status:Implemented Syntax: shell [system_command] Comments: system_command is the command which is to be run in interpreter.It is to be passed as an argument. Run 'exit' command to return to gnucap command interpreter.

gnucap:user:showmod

12.SHOWMOD Purpose:Lists model parameter values Status:Done

gnucap:user:source

13.SOURCE Purpose:Reads a gnucap input file Status:Done

gnucap:user:strcmp

14.STRCMP Purpose:Compares two string Status:Implemented Syntax: strcmp string1 string2 strcmp --help Comments: Compare two strings and outputs 0 if the two strings are equal otherwise output is the difference of the first non-matching character in string1 and string2. Strings may be passed with or without ” ”.

gnucap:user:sysinfo

15.SYSINFO Purpose:Command prints the system information Status:Implemented Syntax: sysinfo Comments: Command prints the useful system information which users may use to send bug reports to the gnucap developers community. This command doesn't works on Windows.

gnucap:user:test

test

gnucap:user:test_test

test test this is a test another page one more

gnucap:user:trace

16.TRACE Purpose:Trace command traces nodes Status:Not implemented

gnucap:user:unalias

17.UNALIAS Purpose:Removes the definition for each alias name specified. Status:Implemented Syntax: unalias [word] unalias all Comments: word is the aliased name of the command. all option removes all the specified aliases. Example: If info is the aliased name of sysinfo then it can be unaliased like

gnucap:user:undef

18.UNDEF Purpose:Command removes the the user-defined functions. Status:Implemented Syntax: undef [function_name] undef all Comments: all flag removes all the user defined functions. Example: gnucap>undef max Removes the ''max'' function gnucap>unalias all Removes all function definitions are you sure you want to remove all function definitions?y/n:y all functions removed. gnucap>

gnucap:user:user

This page provides an area for users to make contributions. To add yours .... * Create an account for yourself * Edit this page to add a link to the new page you will make * Make the new page for your contribution. ---------- Noise implementation - here is all stuff related to .noise command implementation: syntax, noise calculation basics, discussions regarding noise implementation and code-related stuff. Noise command implementation is not complete yet, so all material have “workin…

gnucap:user:version

19.VERSION Purpose:Prints the version of gnucap being used Status:Implemented Syntax: version Comments: 'ver' also works. Example: gnucap> version Gnucap Version: 2009.12.07 RCS 26.136 gnucap>

gnucap:user:while_statement

while statement Purpose: This command executes the statements defined within its body until the condition specified evaluates to true as soon as the condition evaluates to false looping stops. Status: Done.Nesting is not supported at the moment. Syntax: