The Tcl command to run synthesis is synth_design
. Typically, this command is run with multiple options, for
example:
synth_design -part xc7k30tfbg484-2 -top my_top
In this example, synth_design
is run with the -part
option and the -top
option.
In the Tcl Console, you can set synthesis options and run synthesis using Tcl
command options. To retrieve a list of options, type synth_design -help
in the Tcl Console. The following snippet is an example
of the -help
output: synth_design -help
.
Description:
Synthesize a design using Vivado Synthesis and open that design
Syntax:
synth_design [-name <arg>] [-part <arg>] [-constrset <arg>] [-top <arg>]
[-include_dirs <args>] [-generic <args>] [-verilog_define <args>]
[-flatten_hierarchy <arg>] [-gated_clock_conversion <arg>]
[-directive <arg>] [-rtl] [-bufg <arg>] [-no_lc]
[-shreg_min_size <arg>] [-mode <arg>]
[-fsm_extraction <arg>][-rtl_skip_mlo][-rtl_skip_ip]
[-rtl_skip_constraints]
[-keep_equivalent_registers] [-resource_sharing <arg>]
[-cascade_dsp <arg>] [-control_set_opt_threshold <arg>]
[-max_bram <arg>] [-max_uram <arg>]
[-max_dsp <arg>] [-max_bram_cascade_height <arg>]
[-max_uram_cascade_height <arg>] [-global_retiming]
[-no_srlextract]
[-assert] [-no_timing_driven] [-sfcu] [-debug_log] [-quiet] [-verbose]
Returns:
design object
Usage:
Name Description
------------------------------------------------------------------------------------------------
[-name] Design name
[-part] Target part
[-constrset] Constraint fileset to use.
[-top] Specify the top module name.
[-include_dirs] Specify verilog search directories.
[-generic] Specify generic parameters. Syntax: -generic
<name>=<value> -generic <name>=<value> ...
[-verilog_define] Specify verilog defines. Syntax:
-verilog_define <macro_name>[=<macro_text>]
-verilog_define <macro_name>[=<macro_text>]
[-flatten_hierarchy] Flatten hierarchy during LUT mapping. Values:
zull, none, rebuilt.
Default: rebuilt
[-gated_clock_conversion] Convert clock gating logic to flop enable.
Values: off, on, auto
Default: off
[-directive] Synthesis directive. Values: default,
RuntimeOptimized, AreaOptimized_high,
AreaOptimized_medium, AlternateRoutability,
AreaMapLargeShiftRegToBRAM,
AreaMultThresholdDSP, FewerCarryChains.
Default: default
[-rtl] Elaborate and open an rtl design.
[-bufg] Max number of global clock buffers used by synthesis.
Default = 12
[-no_lc] Disable LUT combining. Do not allow combining.
[-shreg_min_size] Minimum length for chain of registers to be mapped onto
SRL.
Default: 3
[-mode] The design mode. Values: default, out_of_context.
Default: default
[-fsm_extraction] FSM Extraction Encoding. Values: off, one_hot,
sequential, johnson, gray, user_encoding, auto.
Default: auto
[-rtl_skip_mlo] Skip mandatory logic optimization for RTL elaboration of
the design; requires -rtl option.
[-rtl_skip_ip] Exclude subdesign checkpoints in the RTL elaboration of
the design; requires -rtl option.
[-rtl_skip_constraints] Do not load and validate constraints against elaborated
design; requires -rtl option.
[-srl_style] Static SRL Implementation Style. Values: register,
srl, srl_reg, reg_srl, reg_srl_reg.
[-keep_equivalent_registers] Prevents registers sourced by the same logic from being
merged. (Note that the merging can otherwise be
prevented using the synthesis KEEP attribute).[-resource_sharing] Sharing arithmetic operators. Value: auto, on, off.
Default: auto
[-cascade_dsp] Controls how adders summing DSP block outputs will be
implemented. Value: auto, tree, force.
Default: auto
[-control_set_opt_threshold] Threshold for synchronous control set optimization to
lower number of control sets. Valid values are 'auto'
and non-negative integers. The higher the number, the
more control set optimization will be performed and
fewer control sets will result. To disable control set
optimization completely, set to 0.
Default: auto
[-max_bram] Maximum number of block RAM allowed in design. (Note -1
means that the tool will choose the max number allowed
for the part in question).
Default: -1
[-max_uram] Maximum number of UltraRAM blocks allowed in design.
(Note -1 means that the tool will choose the max number
allowed for the part in question).
Default: -1
[-max_dsp] Maximum number of block DSP allowed in design. (Note -1
means that the tool will choose the max number allowed
for the part in question).
Default: -1
[-max_bram_cascade_height] Controls the maximum number of BRAM that can be cascaded
by the tool. (Note -1 means that the tool will choose
the max number allowed for the part in question).
efault: -1
[-max_uram_cascade_height] Controls the maximum number of UtraRAM that can be
cascaded by the tool. (Note -1 means that the tool will
choose the max number allowed for the part in question).
Default: -1
[-global_retiming] Seeks to improve circuit performance for intra-clock
sequential paths by automatically moving registers
(register balancing) across combinatorial gates or LUTs.
It maintains the original behavior and latency of the
circuit and does not require changes to the RTL sources. A value of "on" turns on retiming, "off" turns off retiming and "auto" will allow the tool to decide. "auto" will have retiming turns on for Vesal devices and off for non-Versal devices. Default: "auto"
[-no_srlextract] Prevents the extraction of shift registers so that they
get implemented as simple registers.
[-assert] Enable VHDL assert statements to be evaluated. A
severity level of failure will stop the synthesis flow
and produce an error.
[-no_timing_driven] Do not run in timing driven mode.
[-sfcu] Run in single-file compilation unit mode.
[-debug_log] Print detailed log files for debugging.
[-quiet] Ignore command errors.
[-verbose] Suspend message limits during command
For the -generic
option, special handling needs to happen with
VHDL boolean and std_logic_vector
type because those type do not exist
in other formats. Instead of TRUE
, FALSE
, or
0010
, for example, Verilog standards should be given.
For boolean
, the value for FALSE
is:
-generic my_gen=1‘b0
For std_logic_vector
, the value for 0010
is:
-generic my_gen=4‘b0010
-mode
out_of_context
option on the top-level, do not use the PACKAGE_PIN property
unless there is an I/O buffer instantiated in the RTL. The
out_of_context
option tells the tool to not infer any I/O buffers
including tristate buffers. Without the buffer, you get errors in placer.A verbose version of the help is available in the Vivado Design Suite Tcl Command Reference Guide (UG835). To determine any Tcl equivalent to a Vivado IDE action, run the command in the Vivado IDE and review the content in the Tcl Console or the log file.