gh_discussions/Runtime/3604.md

# How do I find out which nets detailed placed failed on?

Tool: Detailed Placement

Subcategory: Timing constraint issue

## Conversation

### oharboe
If I try to bump mock-array frequency from 8000ps to 1000ps, I get detailed placement errors.

How do I find out which nets detailed placement is failing for?

```
[INFO DPL-0035]  hold7527
[INFO DPL-0035]  hold7527
[INFO DPL-0035]  hold19172
[INFO DPL-0035]  hold33345
[INFO DPL-0035]  hold33345
[INFO DPL-0035]  hold33346
[INFO DPL-0035]  hold1805
[INFO DPL-0035]  hold19173
[INFO DPL-0035]  hold7528
[INFO DPL-0035]  input2044
[ERROR DPL-0036] Detailed placement failed.
Error: cts.tcl, 90 DPL-0036
Command exited with non-zero status 1
Elapsed time: 1:53.31[h:]min:sec. CPU time: user 113.09 sys 0.19 (99%). Peak memory: 792296KB.
make: *** [Makefile:579: results/asap7/mock-array/base/4_1_cts.odb] Error 1
```


### oharboe
Change I tried:

```
$ git show
commit be3fd43658747fa25b16fd7fb7317a36e92d7362 (HEAD)
Author: Øyvind Harboe <oyvind.harboe@zylin.com>
Date:   Tue Jul 11 09:01:30 2023 +0200

    mock-array: reduce clock period to 1000ps from 8000ps
    
    Signed-off-by: Øyvind Harboe <oyvind.harboe@zylin.com>

diff --git a/flow/designs/asap7/mock-array/Element/constraints.sdc b/flow/designs/asap7/mock-array/Element/constraints.sdc
index 1d817bb8..0a66e62e 100644
--- a/flow/designs/asap7/mock-array/Element/constraints.sdc
+++ b/flow/designs/asap7/mock-array/Element/constraints.sdc
@@ -4,7 +4,7 @@ set cols [expr {[info exists ::env(MOCK_ARRAY_COLS)] ? $::env(MOCK_ARRAY_COLS) :
 
 set clk_name clock
 set clk_port_name clock
-set clk_period 8000
+set clk_period 1000
 
 set clk_port [get_ports $clk_port_name]
 create_clock -period $clk_period -waveform [list 0 [expr $clk_period / 2]] -name $clk_name $clk_port
diff --git a/flow/designs/asap7/mock-array/constraints.sdc b/flow/designs/asap7/mock-array/constraints.sdc
index ad66e12c..7370cc7f 100644
--- a/flow/designs/asap7/mock-array/constraints.sdc
+++ b/flow/designs/asap7/mock-array/constraints.sdc
@@ -1,6 +1,6 @@
 set sdc_version 2.0
 
-set clk_period 8000
+set clk_period 1000
 create_clock [get_ports clock] -period $clk_period -waveform [list 0 [expr $clk_period/2]]
 
 set clk_name  clock
```


### maliberty
Was this after the abutment PR?  If so you should retry again after https://github.com/The-OpenROAD-Project/OpenROAD-flow-scripts/pull/1221 as that opens up rows in the core.