Using deltaDebug.py to whittle down detailed routing example

[oharboe]

I have some violations that detailed routing isn't able to deal with, that I really think it should be able to deal with.

Normally, deltaDebug.py needs an error message to look for to do it's bisection.

However, a detailed route can succeed after 64 iterations, even if all violations are not sorted out, so there's no error message for deltaDebug.py to use for it's bisection.

Tips?

[maliberty]

Can you use --use_stdout & --error_string to check the final drcs?

[oharboe]

There isn't anything to search for in terms of an error message.

Hmmm... I'll try to define output of "[INFO DRT-0195] Start 64th optimization iteration." as an error condition. That should work...

[INFO DRT-0195] Start 64th optimization iteration.
    Completing 10% with 140 violations.
    elapsed time = 00:00:00, memory = 26140.91 (MB).
    Completing 20% with 140 violations.
    elapsed time = 00:00:12, memory = 26141.38 (MB).
    Completing 30% with 140 violations.
    elapsed time = 00:00:12, memory = 26141.38 (MB).
    Completing 40% with 140 violations.
    elapsed time = 00:00:13, memory = 26141.38 (MB).
    Completing 50% with 140 violations.
    elapsed time = 00:00:23, memory = 26142.46 (MB).
    Completing 60% with 140 violations.
    elapsed time = 00:00:23, memory = 26142.46 (MB).
    Completing 70% with 140 violations.
    elapsed time = 00:00:24, memory = 26142.46 (MB).
    Completing 80% with 140 violations.
    elapsed time = 00:00:25, memory = 26142.46 (MB).
    Completing 90% with 140 violations.
    elapsed time = 00:00:25, memory = 26142.46 (MB).
    Completing 100% with 140 violations.
    elapsed time = 00:00:26, memory = 26142.46 (MB).
[INFO DRT-0199]   Number of violations = 140.
Viol/Layer          M4
eolKeepOut         140
[INFO DRT-0267] cpu time = 00:04:25, elapsed time = 00:00:26, memory = 26142.46 (MB), peak = 29553.55 (MB)
Total wire length = 1530196 um.
Total wire length on LAYER M1 = 0 um.
Total wire length on LAYER M2 = 800022 um.
Total wire length on LAYER M3 = 398406 um.
Total wire length on LAYER M4 = 260445 um.
Total wire length on LAYER M5 = 63003 um.
Total wire length on LAYER M6 = 4158 um.
Total wire length on LAYER M7 = 4160 um.
Total wire length on LAYER M8 = 0 um.
Total wire length on LAYER M9 = 0 um.
Total wire length on LAYER Pad = 0 um.
Total number of vias = 395374.
Up-via summary (total 395374):.

-----------------
 Active         0
     M1     28040
     M2    143080
     M3    161380
     M4     61668
     M5      1102
     M6       104
     M7         0
     M8         0
     M9         0
-----------------
           395374


[INFO DRT-0198] Complete detail routing.
Total wire length = 1530196 um.
Total wire length on LAYER M1 = 0 um.
Total wire length on LAYER M2 = 800022 um.
Total wire length on LAYER M3 = 398406 um.
Total wire length on LAYER M4 = 260445 um.
Total wire length on LAYER M5 = 63003 um.
Total wire length on LAYER M6 = 4158 um.
Total wire length on LAYER M7 = 4160 um.
Total wire length on LAYER M8 = 0 um.
Total wire length on LAYER M9 = 0 um.
Total wire length on LAYER Pad = 0 um.
Total number of vias = 395374.
Up-via summary (total 395374):.

-----------------
 Active         0
     M1     28040
     M2    143080
     M3    161380
     M4     61668
     M5      1102
     M6       104
     M7         0
     M8         0
     M9         0
-----------------
           395374


[INFO DRT-0267] cpu time = 102:26:08, elapsed time = 12:15:27, memory = 26144.38 (MB), peak = 29553.55 (MB)

[INFO DRT-0180] Post processing.
Elapsed time: 12:33:34[h:]min:sec. CPU time: user 363816.58 sys 6611.14 (819%). Peak memory: 36869740KB.

[maliberty]

You could make a temporary change to scripts/detail_route.tcl to call detailed_route_num_drvs and issue an error message if >0. Then you could delta on that.

[oharboe]

Turns out deltaDebug.py doesn't care about exit code, only the presence of a string. In my case, if it gets to the 64th iteration in detailed routing, then I assume there are violations, which is good enough to run bisection:

Reading base odb file
Writing odb file
Step 0 is running, deltaDebug is waiting.
Timeout updated to approx 610 minutes!
Error Code found: [INFO DRT-0195] Start 64th optimization iteration.
Step 0 is done.

[oharboe]

Various bugs have been fixed and improvements made to deltaDebug.py since this post.