we could have a call later today if it helps

Question

< U016HU5HK8V> we could have a call later today if it helps going through the antenna stuff

tnt · Answer

Thanks But if a fix is coming in openroad to place the diode in the grid rather than outside I guess I d have to wait for that first anyway unless you have any other suggestions

mehdi · Answer

Yes I think it makes sense to wait for the fix

mehdi · Answer

< U016HU5HK8V> < U01634FSETZ> < U016HSALFAN> Following is the fixed for Sylvain s issue

Riking28 · Answer

That s a private sweat smile

tnt · Answer

< Riking28> < mehdi> yeah I was about to say the same

mehdi · Answer

Yeah I tagged < Amr Gouhar> since he has access so he could try it or help you guys have this in openlane

Amr Gouhar · Answer

< mehdi> I don t think niether Ghazy nor I have access to that repository

mehdi · Answer

Oh I see I was told efabless has access I will check

Ahmed Ghazy · Answer

< mehdi> Nope don t have access either

tnt · Answer

< mehdi> If it s a single patch can you email it or post it here

mehdi · Answer

< tnt> Eder made a for here

mehdi · Answer

fork

mehdi · Answer

Can you try it and let me know

tnt · Answer

Ack I ll test that

tnt · Answer

< mehdi> So the `flute3` submodule on that branch points to a commit that doesn t exist in the public repo is that an issue or can I use the older `flute3`

mehdi · Answer

< tnt> the older `flute3` should be fine

tnt · Answer

< mehdi> Well the good news is that it didn t place diode outside the grids It went all the way through the flow The bad news is this ended with ```Number of pins violated 27 Number of nets violated 24```

mehdi · Answer

< tnt> are those the remaining antenna violations

tnt · Answer

yes

mehdi · Answer

How many were remaining the previous time

tnt · Answer

Let me re do a run changing just the diode strategy to make sure it s the only variable

Amr Gouhar · Answer

< tnt> you can try increasing ` env GLB RT MAX DIODE INS ITERS `

tnt · Answer

< Amr Gouhar> Ah thanks I ll give that a shot too

tnt · Answer

< mehdi> < Amr Gouhar> So with Spray stragery `1` I get `5 pin 5 net` violations When increasing `GLB RT MAX DIODE INS ITERS` to `5` then I get `38 pin 35 net` confused

Amr Gouhar · Answer

< tnt> Then it s a tradeoff between area and number of antenna violations But it s interesting that the diveregence avoidance during the iterations didn t work Can you check the log files for each iteration and confirm that it did choose the DEF file with the lowest antenna violations or share your testcase

tnt · Answer

< Amr Gouhar> yeah the increase was probably due to slight change in density the spray method wouldn t route so I had to tweak it Trying now on the complete design previous was just a reduced one which has more free room but doesn t look promising the fast route finished with still antenna violations reported

tnt · Answer

yeah indeed fina checks reports plenty of error confused

tnt · Answer

tnt · Answer

Design has plenty of free space

tnt · Answer

Most of the failure seem to happen on input pins basically

tnt · Answer

input to the whole design I mean

tnt · Answer

But something more worrying is that it also breaks LVS confused

mehdi · Answer

< tnt> 24 antenna violations isn t that bad tbh

tnt · Answer

I thought we were supposed to get to 0 for submission

mehdi · Answer

we are working on making a heuristic loop that would fix all the violations but I am not sure about the timeline

mehdi · Answer

yes we have to have 0 antenna I think

Riking28 · Answer

Fab tweaks can happen after nov30 I think

Riking28 · Answer

There are unimplemented drc rules and somebody s going to hit them

mehdi · Answer

< tnt> What is the status on this Sorry I have a few deadlines coming and lost track on this

tnt · Answer

The branch you pointed to does indeed places diode on the grid now but 1 still plenty of violations left and 2 when running multiple iterations it does very bad things <https app slack com client T01699QAZBQ C016H8WJMBR thread C016ULUQXDF 1606339001 245400>

tnt · Answer

Sorry bad link <https skywater pdk slack com archives C016H8WJMBR p1606384183186000>

tnt · Answer

see the thread in channel not as replies

mehdi · Answer

Thanks checking I am suspecting the extra legalization after each iteration is creating issues

mehdi · Answer

< U016HU5HK8V> Sorry I have had a couple deadlines this week Could you please check There is an option to set the number of iterations in the Tcl script so these weird things are not supposed to happens The new syntax of repair antennas is `repair antennas diode name iterations` Example for sky130 repair antennas sky130 fd sc hs diode 2 DIODE 3

tnt · Answer

< mehdi> Ok I ll give that a shot probably this weekend and report back

tnt · Answer

< mehdi> It doesn t build

tnt · Answer

There are some missing ` include` I was able to fix but the OpenDB submodule points to a non existant non public commit I tried building it with the same commit as OpenROAD master points to but it ends up in error

mehdi · Answer

Ok will check

tnt · Answer

Mm actually I think it was some stale swig autogenerated files that didn t get rebuilt automatically

tnt · Answer

I mean the OpenDB commit is definitely not public but not sure if it s needed for that branch to work or not

mehdi · Answer

I did not try it with the public stuff But it builds fine

tnt · Answer

I used `7d78630dce0b6b50a091b7ae0ae8d0ffcbf6b38e` for OpenDB instead of the `948108aec398bb418ff46c59b75faf76d39b8140`

tnt · Answer

yeah deleting the whole build dir and restarting from scratch worked it just didn t like just doing an incremental build

tnt · Answer

Mmm looks like something else changed and it doesn t work with the openlane script

tnt · Answer

`Error or route tcl 54 Wrong number of arguments FastRoute run fastroute onlySignal argument 1`

tnt · Answer

On <https github com efabless openlane blob develop scripts openroad or route tcl L54>

mehdi · Answer

Ahh Still did not use openlane yet Maybe check with < Ahmed Ghazy> what s the best way I am not close to my machine rn

tnt · Answer

Is there a documentation of what the new syntax for `FastRoute run fastroute` is

tnt · Answer

Obviously it wants some arguments now

mehdi · Answer

There are documentation on tbe github link I sent you

Ahmed Ghazy · Answer

`FastRoute run fastroute 0` probably

mehdi · Answer

Yes

tnt · Answer

that s what I ended up trying run in progress

tnt · Answer

Nope still screws with the orientation of the cells

tnt · Answer

Actually it maybe have flipped them all

tnt · Answer

And again with a single iteration I don t get the issue And this is with the built in multi iteration thing I disabled the while look in openlane that was manually running fast route several times and modified it to call repair antenna with the number of iterations directly It s also unlocking placement of some stuff like I have the SRAM macros marked as `FIXED` and fastroute puts them as `PLACED`