Command Reference 2. Synopsys Commands create_schematic
NAME
create_schematic
Generates a schematic for the current
design.
SYNTAX
int create_schematic [-hierarchy] [-size sheet_size] [-portrait]
[-fill_percent fill_value] [-no_bus] [-outputs_attract]
[-order_outputs output_port_list]
[-sort_outputs] [-dont_left_justify_inputs]
[-symbol_view] [-hier_view] [-schematic_view]
[-implicit] [-bit_mappers] [-sge]
[-no_type_mappers] [-reference] [-no_rippers]
string sheet_size
float fill_value
list output_port_list
ARGUMENTS
-hierarchy Generates a schematic and/or symbol for
each design in the hierarchy below the
current design.
-size sheet_size
Specifies schematics' sheet size for
each design. The create_schematic
command uses the sheet symbol in either
the symbol_library or the
generic_symbol_library with its template
attribute the same as sheet_size. For
more information on this option, see the
Description section.
-portrait Non-infinite sheets are normally
formatted so they are horizontally
oriented (commonly referred to as
landscape orientation). -portrait tells
the schematic generator to use sheets
that are vertically oriented (portrait
orientation).
-fill_percent fill_value
Normally, the maximum area of sheets is
filled. -fill_percent instructs the
schematic generator to use a fraction of
the available space. This may be
desirable, for example, if you plan to
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create_schematic 2. Synopsys Commands Command Reference
add graphics to a schematic manually.
-fill_percent expects a value between 0
and 100. The default value is 100.
-no_bus Specifies that a schematic is to be
generated without bussing. When
creating a bussed schematic, bussed nets
are determined from bussed ports and
pins in the design. Bussed nets in the
schematic are not created directly from
bussed nets in the design. For more
information on this option, see the
Description section.
-outputs_attract
Normally, if a cell drives both an
output port and another cell, it is
placed near the cell, not the output
port. -outputs_attract causes a cell
that drives an output port to be placed
near the port.
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Command Reference 2. Synopsys Commands create_schematic
-order_outputs output_port_list
By default, placement of cells on a
schematic is determined solely by
connectivity. With -order_outputs, you
can specify a desired placement order of
outputs. This causes the placement of
the output ports to approach the order
specified in output_port_list (from top
to bottom). The output ports might not
be ordered exactly as specified, because
they are still placed near their driving
cells. But the cell placement is
altered to try to accommodate the
desired order of output ports. For more
information on -order_outputs, see the
Description section.
-sort_outputs Performs the same actions as
-output_order, except that the order of
the outputs is determined by sorting
them alphanumerically.
Note: "OUT10" comes after "OUT2" in this
alphanumeric sort.
-dont_left_justify_inputs
Normally, all input ports are aligned to
the far left side of the schematic.
With this option, input ports are placed
near the cell driven by the port.
-symbol_view Creates the symbol view for the current
design.
-hier_view Creates hierarchical views for the
current design.
-schematic_view
Creates only a schematic for the current
design. This is the default if no other
view is specified.
-implicit Generates "implicit" name-based
connections for bussed nets. See
"bussing" in the Description section.
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create_schematic 2. Synopsys Commands Command Reference
-bit_mappers Turns on generation of bit mapper
symbols for bus-to-bus connections. See
"bussing" in the Description section.
-sge Creates schematics compatible with the
SGE environment. Use this option to
generate schematics that will be
transferred to SGE through the db2sge
tool.
-no_type_mappers
Turns off the generation of type mapper
symbols on top level design ports for
the -sge option. Without this option,
SGE schematics will have the type_mapper
symbols attached to the design ports of
the top level design.
-reference Creates the schematic for the design of
the current instance.
-no_rippers Creates the schematic without any
rippers. The rippers are disconnected
from the schematic. The connections to
busses are made on the basis of the name
of the bit being ripped off.
DESCRIPTION
Generates a schematic for the current design according
to the arguments specified.
The default generic_symbol_library provided by Synopsys
contains sheet template symbols in both landscape and
portrait orientation for these common sheet sizes: "A",
"B", "C", "D", "E", "A0", "A1", "A2", "A3", "A4". The
default library also contains a symbol called
"mentor_maximum" that is 109 by 109 inches, the maximum
sheet size allowed by Mentor when pin spacing is 0.10
inches.
If sheet_size is set to "infinite" (default value),
create_schematic places the schematics on a single
sheet of an appropriate size. Otherwise,
create_schematic uses as many sheets of the specified
size as are required for the schematics.
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Command Reference 2. Synopsys Commands create_schematic
For bussed schematics, create_schematic uses one type
of ripper symbol to indicate that either one member or
a range of members (or sub-bus) is extracted from a
bus. An instance of this symbol is rotated 180 degrees,
if needed.
When create_schematic is invoked with the -bit_mappers
option, bus-to-bus connections are shown with bit
mapper symbols. The name of the bit mapper in the
bit_mapper_name_layer represents the connectivity of
the two bus segments connected by the bit mapper. For
example, if there are two busses A[0:16] and B[0:10] in
the schematic, and A[0], A[1] and A[5] connect to
B[10], B[6] and B[5] respectively, there will be a bit
mapper between A and B and its name will be A[0:1],
A[5] == B[10], B[6:5] These bit mapper symbols replace
the ladders in the earlier schematics.
When -implicit is turned on, any bus segments that span
more than one column are not shown on the schematic.
There are small net segments attached to the pins
connected by any such bus segments and these contain
the name of the bus bits connecting to the pin. For
example, if bus pin U31/A[0:4] has A[0:2] connected to
bus IN[3:1], A[3] unconnected, and A[4] connected to
bus PI[5], the pin's attached net would have the name
IN[3:1], U31/A[4], PI[5] indicating its connectivity in
the bus_compound_name_layer. Any such bus segments in
adjacent columns are still shown connected by rippers.
This can be suppressed by setting the
gen_bussing_exact_implicit variable to TRUE.
Bussed objects are named according to the naming
convention specified by the schematic_variable,
gen_bus_member_naming_style.
When -order_outputs or -sort_outputs is used, the
output ports might not be ordered exactly as specified.
An instance of when output ports might be different
from the specified order, is when two ports are driven
by two outputs of a single cell. In this case, the
order of the ports is determined by the order of the
pins on the symbol for the cell.
Another instance might be when a port is driven by a
cell in the middle of a schematic. In this case, the
port is placed as close as possible to the routing of
the port's net. The restriction that ports be driven
from the middle of the schematic, is removed with
-outputs_attract.
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create_schematic 2. Synopsys Commands Command Reference
EXAMPLES
This example generates an infinite-sheet schematic for
the current design:
dc_shell> create_schematic
This example generates a schematic of the current
design and all the designs it uses on A size sheets:
dc_shell> create_schematic -hierarchy
-size A
This example creates the symbol view of the current
design:
dc_shell> create_schematic -symbol_view
This example creates all symbol views of designs in the
hierarchy:
dc_shell> create_schematic -hierarchy
-symbol_view
This example generates only a schematic of the current
design:
dc_shell> create_schematic
-schematic_view
The following example generates a schematic of the
current design on D size sheets, using only half of the
available space on each sheet; and orients the sheets
so that they are laid out vertically (portrait
orientation).
dc_shell> create_schematic -fill_percent
50 -portrait
The following example generates a schematic with all
cells that drive output ports close to their ports, and
organizes the schematic so that the order of the
outputs tends to follow the order of the pins in the
database. Also, the example places input pins near the
cells they drive, not necessarily at the far left of
the schematic.
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Command Reference 2. Synopsys Commands create_schematic
dc_shell> create_schematic -order_outputs all_outputs( )\
-outputs_attract -dont_left_justify_inputs
SEE ALSO
all_outputs(2), plot(2), report_xref(2); db2sge(1);
schematic_variables(3).
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