Skip to content

Commit 6a7f245

Browse files
committed
yamlfix variables.yaml
Signed-off-by: Jack Luar <[email protected]>
1 parent a50fc37 commit 6a7f245

File tree

1 file changed

+0
-13
lines changed

1 file changed

+0
-13
lines changed

flow/scripts/variables.yaml

-13
Original file line numberDiff line numberDiff line change
@@ -14,7 +14,6 @@ GENERATE_ARTIFACTS_ON_FAILURE:
1414
congestion, is not a build failure(as in exit code non-zero), it is a
1515
successful(as in zero exit code) global route that produce reports
1616
detailing the problem.
17-
1817
Detailed route will not proceed, if there is global routing congestion
1918
This allows build systems, such as bazel, to create artifacts for global and
2019
detailed route, even if the operation had problems, without having know
@@ -42,18 +41,15 @@ ROUTING_LAYER_ADJUSTMENT:
4241
but risk excessive detours and long global routing times,
4342
while low values reduce global routing failure but can
4443
complicate detailed routing.
45-
4644
The global routing running time normally reduces
4745
dramatically(entirely design specific, but going from hours to
4846
minutes has been observed) when the value is
4947
low(such as 0.10).
50-
5148
Sometimes, global routing will succeed with lower values and
5249
fail with higher values. Exploring results with different
5350
values can help shed light on the problem. Start with
5451
a too low value, such as 0.10, and bisect
5552
to value that works by doing multiple global routing runs.
56-
5753
As a last resort, `make global_route_issue` and using
5854
the tools/OpenROAD/etc/deltaDebug.py can be useful to debug
5955
global routing errors. If there is something specific that is
@@ -401,17 +397,13 @@ HOLD_SLACK_MARGIN:
401397
Specifies a time margin for the slack when fixing hold violations.
402398
This option allows you to overfix or underfix(negative value, terminate
403399
retiming before 0 or positive slack).
404-
405400
floorplan.tcl uses min of HOLD_SLACK_MARGIN and 0(default hold slack margin).
406-
407401
This avoids overrepair in floorplan for hold by default, but allows skipping
408402
hold repair using a negative HOLD_SLACK_MARGIN.
409-
410403
Exiting timing repair early is useful in exploration where
411404
the .sdc has a fixed clock period at the design's target clock period and where
412405
HOLD/SETUP_SLACK_MARGIN is used to avoid overrepair(extremely long running
413406
times) when exploring different parameter settings.
414-
415407
When an ideal clock is used, that is before CTS,
416408
a clock insertion delay of 0 is used in timing paths. This creates
417409
a mismatch between macros that have a .lib file from after CTS, when
@@ -422,20 +414,16 @@ HOLD_SLACK_MARGIN:
422414
macros built with OpenROAD. This is less accurate than if OpenROAD had
423415
created a placeholder clock tree for timing estimation purposes
424416
prior to CTS.
425-
426417
There will inevitably be inaccuracies in the timing calculation prior
427418
to CTS. Use a slack margin that is low enough, even negative, to
428419
avoid overrepair. Inaccuracies in the timing prior to CTS can also
429420
lead to underrepair, but there no obvious and simple way to avoid
430421
underrapir in these cases.
431-
432422
Overrepair can lead to excessive runtimes in repair or too much buffering
433423
being added, which can present itself as congestion of hold cells or
434424
buffer cells.
435-
436425
Another use of SETUP/HOLD_SLACK_MARGIN is design parameter exploration
437426
when trying to find the minimum clock period for a design.
438-
439427
The SDC_FILE for a design can be quite complicated and instead of
440428
modifying the clock period in the SDC_FILE, which can be non-trivial,
441429
the clock period can be fixed at the target frequency and the
@@ -451,7 +439,6 @@ SETUP_SLACK_MARGIN:
451439
Specifies a time margin for the slack when fixing setup violations.
452440
This option allows you to overfix or underfix(negative value, terminate
453441
retiming before 0 or positive slack).
454-
455442
See HOLD_SLACK_MARGIN for more details.
456443
stages:
457444
- cts

0 commit comments

Comments
 (0)