This command route_auto seemingly nothing changes, but the content has changed.
Remember like said before, for high-speed design, we recommend using a trilogy, rather than directly using route_auto:
route_global
update_timing
route_track
update_timing
route_detail
update_timing
Trilogy, behind every order comes with update_timing. Because all timing driven trilogy, the first priority to critical path around, try to get them straight. After route_global, critical path changes certainly somewhat, so in order to make route_track see the real critical path, need update_timing. route_detail is the same principle.
And now route_auto upgrade, which comes update_timing, so the effect and Trilogy + update_timing basically the same. Means no longer need trilogy!
Timing driven route_global
timing driven global route (route.global.timing_driven) have already been made, but now have to upgrade for advanced technology, in the middle of global route will update_timing.
In fact, similar principles and just said route_auto trilogy. route_auto divided three steps, route_global can be divided into several phase: GR phase 0, GR phase 1, GR phase 2 ...... phase and the middle phase is not the original update_timing, which is likely to see will phase 1/2/3 it is not the most real critical path, for WNS, it is not the best.
Now, with a new app option: route.global.advance_node_timing_driven_effort, it makes global route after GR phase 3 to make a update_timing, and then continue to do GR phase twelve based on the updated timing, so the timing will get better .
This app option default is high, so no need to set.
crosstalk driven global route
This feature (route.global.crosstalk_driven) is also very early. But before actually nothing set no effect. why? Just because the routing global glink, not real metal, so do not see crosstalk.
The latest version of the upgrade, even global route, you could see the crosstalk. Of course, the crosstalk value is estimated by the algorithm out, and the true crosstalk also some differences, but better than nothing.
After GR With crosstalk, there is a benefit, is to take the GRO / GRE flow time (based on global route do timing optimization, see the link at the end), can see the timing with the SI, SI repair than the post-route at this stage SI repair is much easier, so timing can be changed for the better.
In a recent case a few years, to see open crosstalk driven global route, WNS has many benefits, TNS is little change. So to compare the ultimate pursuit of WNS students can try crosstalk driven GR + GRE.