Product Documentation
Connectivity to Schematic User Guide
Product Version IC23.1, June 2023

3


Working In Standalone Mode

The Connectivity-to-Schematic tool can be run either from the Virtuoso® Design Environment workbench or in the standalone mode. This chapter describes the command to run the Connectivity-to-Schematic tool in the standalone mode, the parameter file options, and the command-line options.

Starting Connectivity-to-Schematic in Standalone Mode

The standalone executable, conn2sch can be accessed from the following directory:

<inst_dir>/tools/dfII/bin

The command to start the Connectivity-to-Schematic tool is:

conn2sch -lib <libName> -cell <cellName> -view <viewName> [-param <paramFileName>] [-destlib <destLibName>] [-destview <destViewName>] [-cdslib <cdsLibFileName] [-f <optionsFileName] [-log <logFileName>] [+place_only] [-fast_labels] [-help] [-version] [-min_crossovers] [-nosquare] [-asg] [+noxtrsch] [-overdense] [-verbose]

The -lib, -cell, and -view are mandatory command-line options. The command-line options are not case-sensitive.

Using the Command-line Options

The following table describes the command-line options for the Connectivity-to-Schematic tool:

Option Description

-lib <libName>

Specifies the source library name.

-cell <cellName>

Specifies the source cell name.

-view <viewName>

Specifies the source view name.

-param <optionsFileName>

Specifies the name of a conn2sch parameter file.

-destlib <libName>

Specifies the destination library name.

-destview <viewName>

Specifies the destination view name.

-log <logFileName>

Specifies the log file to which the warning and error messages are written. The -log option takes precedence over the log_file_name variable used in the parameter file.

-f

Specifies the file containing all the command line options.

conn2sch -f conn2sch_cmd_opts

where conn2sch_cmd_opts contains all the valid command line options.

-help

Prints a description for the command line options.

-version / -v

Prints the version number.

-over_dense

Generates high-density schematics.

+place_only

Generates a quick unrouted schematic with connectivity indicated by name.

-nosquare

Does not square the schematic; that is, does not manipulate rows and columns of devices to convert a rectangular schematic into a square schematic.

-min_crossovers

Minimizes crossover of nets.

-fast_labels

Enables faster placement of labels. When this option is on, the Connectivity-to-Schematic tool labels segments at the midpoint and does not check for minimum overlap.

+noxtrsch

Does not extract the schematic; that is, does not find errors and warnings that have been written to the OpenAccess databases.

-cdslib <fileName>

Specifies the cds.lib file to be used.

-verbose

Option to print detailed status messages during the schematic placement and routing process.

-asg

Specifies that an analog schematic is to be generated using analog place and route engine.

Creating the Parameter File

You can create a parameter file containing a list of all the options and parameter settings that are used by the Connectivity-to-Schematic tool to generate the schematics. This file can be specified with the -param command-line option while invoking the tool. The command to use a parameter file is:

conn2sch -param paramFile -lib testLib -cell top -view netlist

A sample parameter file, parameter_file.txt, is available in the
<install_directory>/doc/conn2schuser/example directory.

Parameter File Format

Each line in the Connectivity-to-Schematic tool parameter file has a parameter specification statement. The syntax of the parameters follows the Backus Naur format:

parameter_file::= {parameter_specification_statement}

Each parameter specification statement begins with the parameter name followed by the field separator, and then by the value or set of values for the parameter. Following is an example of a parameter specification statement:

parameter_specification_statement::=
parameter_name ps_seperator parameter_value

Parameter name could be any of the following:

parameter_name::=
ref_lib_list |
dest_view_name |
dest_symbol_view_name |
generate_top_cell_symbol |
log_file_name |
import_if_exists |
sheet_symbol |
page_row_limit |
page_col_limit |
label_height |
line_line_spacing |
line_component_spacing |
density_level |
pin_placement |
power_symbol |
ground_symbol |
power_net |
ground_net |
noconn_symbol

The field separator is ‘:=

ps_seperator ::=             :=

You can specify either one value or a set of values separated by a comma for the parameters, as follows:

parameter_value ::=             value, {value}     

The data type of the value can be a string, an integer, or a real number.

value ::= string_value | integer_value | real_value     

In addition, the following rules are applicable for the value:

Following is a sample parameter file:

ref_lib_list := basic, sample, US_8ths
dest_view_name := schematic
dest_symbol_view_name := symbol
generate_top_cell_symbol := 1
log_file_name := ./conn2sch.log
import_if_exists := 0
sheet_symbol := none 
page_row_limt := 1024
page_col_limit := 1024
label_height := 9
line_line_spacing := 0.200000 
line_component_spacing := 0.500000 
density_level := 100 
power symbol := analogLib vdd symbol
ground_symol := analogLib gnd symbol
pin_placement := all_sides
power_net := vdd!
ground_net := gnd!
noconn_symbol := basic noconn symbol

The default log file name is conn2sch.log. The log file name can be specified as an absolute path. By default, the log file is created in the current working directory. If a log file already exists with the same name, it overwrites the existing file.

The command-line option -log takes precedence over the log file name specified in the parameter file.

Parameter File Options

The options used in the schematic generation parameter file are divided into three categories:

General Parameter Options

Option Description

ref_lib_list

Specifies the reference libraries. Use blank space or a comma (,) to separate library names.

ref_lib_list := basic, sample, US_8ths

dest_view_name

Specifies the view name to be used for the generated schematic cellview.

The default view name is schematic.

dest_view_name := schematic

dest_symbol_view_name

Specifies the view name to be used for the generated symbol view.

The default view name is symbol.

dest_symbol_view_name := symbol

generate_top_cell_symbol

Specifies if the symbol of the top cell must be created.

The default value is 0. Set the value to 1 to generate the symbol of the top cell.

generate_top_cell_symbol := 1

log_file_name

Specifies a file that lists all error messages and log messages.

log_file_name := ./conn2sch.log

import_if_exists

Specifies whether to import a cellview for which the schematic view already exists in the target library. When you set this value to 1, the cellview is imported. When you set this value to 0 (default), the cellview is skipped and is indicated in the log file.

import_if_exists := 0

Schematic Generation Parameter Options

Option Description

sheet_symbol

Specifies which sheet border size the Connectivity-to-Schematic tool applies when creating a multi-sheet schematic. The sheet borders reside in the US_8ths library. When this value is none, the Connectivity-to-Schematic tool generates an infinite sheet schematic.

sheet_symbol := none

page_row_limit

Specifies the maximum number of rows on each sheet. Usually, the maximum number of rows is expressed as a number between 1 and 1024. If missing, the limit is automatically set to 1024.

page_row_limit := 1024

page_col_limit

Specifies the maximum number of columns on each sheet. Usually the maximum number of columns is expressed as a number between 1 and 1024. If missing, the limit is automatically set to 1024.

page_col_limit := 1024

label_height

Specifies the size of the font used for pin, wire, and instance labels. The value must be an integer greater than or equal to 1.

label_height := 9

line_line_spacing

Specifies the spacing in inches between nets flowing in a channel. The value must be a real number in the range of 0.125 to 0.625.

line_line_spacing := 0.2

line_component_spacing

Specifies the spacing in inches between a component and the nearest net flowing in a channel. The value must be a real number in the range of 0.125 to 0.625.

line_component_spacing := 0.5

density_level

Specifies the density of the schematic. The input must be an integer from 0 to 100, where 100 is the most dense and 0 is the least dense.

density_level := 100

pin_placement

Specifies the placement of pins on a symbol. Pin placement can be defined in the parameter file with any of the two values: left_and_right_sides or all_sides.

For example:

pin_placement := left_and_right_sides

Alternatively, you can define placement of specific pins on specific sides of a module in a pin placement file, as described in the Pin Placement section. The pin placement file is referred in the parameter file as:

pin_placement := file, pinConn.pl

-noconn_symbol

Connects the floating nets ports in the schematic with the noconn instance.

For example:

noconn_symbol:= basic noconn symbol

Analog Schematic Generation Parameter Options

Option Description

power_symbol

Specifies a cellview, which you need to use as a master of a power cell instance.

power_symbol := analogLib vdd symbol

ground_symbol

Specifies a cellview, which you want to use as a master of a ground cell instance.

ground_symbol := analogLib gnd symbol

power_net

Specifies a power net, which is used to vertically align the instances.

power_net := vdd!

ground_net

Specifies a ground net, which is used to vertically align the instances.

ground_net := gnd!


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