synth - generic synthesis script¶
yosys> help synth
¶
synth [options]
This command runs the default synthesis script. This command does not operate
on partly selected designs.
-top <module>
use the specified module as top module (default='top')
-auto-top
automatically determine the top of the design hierarchy
-flatten
flatten the design before synthesis. this will pass '-auto-top' to
'hierarchy' if no top module is specified.
-encfile <file>
passed to 'fsm_recode' via 'fsm'
-lut <k>
perform synthesis for a k-LUT architecture.
-nofsm
do not run FSM optimization
-noabc
do not run abc (as if yosys was compiled without ABC support)
-booth
run the booth pass to convert $mul to Booth encoded multipliers
-noalumacc
do not run 'alumacc' pass. i.e. keep arithmetic operators in
their direct form ($add, $sub, etc.).
-nordff
passed to 'memory'. prohibits merging of FFs into memory read ports
-noshare
do not run SAT-based resource sharing
-run <from_label>[:<to_label>]
only run the commands between the labels (see below). an empty
from label is synonymous to 'begin', and empty to label is
synonymous to the end of the command list.
-abc9
use new ABC9 flow (EXPERIMENTAL)
-flowmap
use FlowMap LUT techmapping instead of ABC
-no-rw-check
marks all recognized read ports as "return don't-care value on
read/write collision" (same result as setting the no_rw_check
attribute on all memories).
The following commands are executed by this synthesis command:
begin:
hierarchy -check [-top <top> | -auto-top]
coarse:
proc
flatten (if -flatten)
opt_expr
opt_clean
check
opt -nodffe -nosdff
fsm (unless -nofsm)
opt
wreduce
peepopt
opt_clean
techmap -map +/cmp2lut.v -map +/cmp2lcu.v (if -lut)
alumacc (unless -noalumacc)
share (unless -noshare)
opt
memory -nomap
opt_clean
fine:
opt -fast -full
memory_map
opt -full
techmap
techmap -map +/gate2lut.v (if -noabc and -lut)
clean; opt_lut (if -noabc and -lut)
flowmap -maxlut K (if -flowmap and -lut)
opt -fast
abc -fast (unless -noabc, unless -lut)
abc -fast -lut k (unless -noabc, if -lut)
opt -fast (unless -noabc)
check:
hierarchy -check
stat
check