Good morning, I have a question about the `"SYNTH_...
# openlane
l
Good morning, I have a question about the
"SYNTH_STRATEGY"
parameter. What do the values from 0 to 4 represent? With AREA 0 do I get the smallest possible area? With DELAY 0 do I get the maximum clock speed?
v
yes
./flow.tcl -design name -synth_explore
will generate summary to choose best option.
l
Thank you
I don't understand how these values work. I found that the maximum clock frequency is achieved using the AREA3 strategy, but shouldn't it be achieved with DELAY 0? How is this possible?
d
With regards to SYNTH_STRATTEGY, the names should be considered for most intents and purposes arbitrary- ABC behaves chaotically. Frequently AREA 3 has the best delay value, but sometimes it doesn't. We'd change it but that'd be a breaking change (non-backwards compatible.) Presently, we advise that people do their exploration and just pick whatever aligns best with their PPA targets. In a future version of OpenLane (3 or later) we may elect to rename them at the expense of back-compat.
l
Last year I tried some experiments with SYNTH_STRATEGY. Was not satisfied with the results. Not sure if it has changed now.