[mpw-5] OpenLane errors out: [ERROR DRT-0074] No ap for PIN/fastio_in[16].

[armleo]

Description

mpw5a caravel based OpenLane installation.
OpenLane errors out: [ERROR DRT-0074] No ap for PIN/fastio_in[16].

I examined DEF/GDS and everything. There seems no reason for this to happen.

Things I checked:

1. Pin is located inside die area from config.tcl or def die area, which are exactly the same.
2. I suspected that the pin was too small, but increasing or decreasing pin width does not change anything.
3. I suspected that it didn't reach the main logic area, but increasing the length didn't change anything
4. I changed type of the pin from FIXED to PLACED, but didn't get any changes.
5. Used a def generated by OpenLane itself. It works.
6. The pin's layer (met2) matches the direction of the pin.
7. Location in DEF matches the locations in run's def.

Things I didn't check:
Should the pins be located on some grid? Didn't find any information about this. If so, where is it documented?

Why I am trying to use a DEF and not locations generated by OpenLane pin config? Because I can't specify specific locations of the pins, including metal, spacing and width in any other way.

UPD: Tried shifting some pins by 10nm in case of OpenLane generated DEF. Still succesful, so GRID issue is not likely.

Environment

Python: v3.9.5

Kernel: Linux v5.11.0-49-generic

Distribution: ubuntu 21.04

Container Engine: docker v20.10.10

OpenLane Git Version: 2021.11.23_01.42.34

---

PDK Version Verification Status: OK

---

Git Log (Last 3 Commits)



commit e1883edfbcc8c7e96491158521522b7a66541745

Author: Manar <manarabdelatty@aucegypt.edu>

Date:   Mon Nov 22 07:59:18 2021 -0600



    Update resizer (#726)



commit 6245b0e675d0e6751bdfc5362c545efe29d1077c

Author: Manar <manarabdelatty@aucegypt.edu>

Date:   Fri Nov 19 13:38:50 2021 -0600



    Fix sram install (#724)

    

    Also disable by default



commit e0e6fbc1bd90d1c73aae19769d997da8c3c47512

Author: Manar <manarabdelatty@aucegypt.edu>

Date:   Fri Nov 19 12:30:08 2021 -0600



    Add option for enabling/disabling repair_tie_fanout (#722)

    

    * Add option for enabling/disabling repair_tie_fanout

    

    * add escape characters

    

    * Add option for enabling sta report power

Reproduction Material

tar gz containing two designs carrack_wrapper:
carrack_wrapper.tar.gz

carrack wrapper is the workspace used to generate the def with command: ./flow.tcl -interactive -file designs/carrack_wrapper/interactive.tcl

carrack_wrapper_user:
carrack_wrapper_user.tar.gz

carrack_wrapper_user is design that errors out command: ./flow.tcl -design carrack_wrapper_user -tag carrack_wrapper_user -overwrite

Manually generated or_issue archive:
or_issue.tar.gz

or_issue command: python3 ./scripts/or_issue.py -s scripts/openroad/droute.tcl /openlane/designs/carrack_wrapper_user/runs/carrack_wrapper_user/tmp/routing/17-addspacers.def

Successful runs (see "thing I checked") are not included. Reproduction takes about 1 hour and 2GB of space.

Expected behavior

No error and properly placed PnR GDS with pins from my def as an output :)

Logs

[INFO DRT-0165] Start pin access.

[ERROR DRT-0074] No ap for PIN/fastio_in[16].

terminate called after throwing an instance of 'std::runtime_error'

  what():  DRT-0074

[ERROR]: during executing: "openroad -exit /openlane/scripts/openroad/droute.tcl |& tee >&@stdout /openlane/designs/carrack_wrapper_user/runs/carrack_wrapper_user/logs/routing/19-tritonRoute.log"

[ERROR]: Exit code: 1

[ERROR]: Last 10 lines:

child killed: SIGABRT



[ERROR]: Please check openroad  log file

[ERROR]: Dumping to /openlane/designs/carrack_wrapper_user/runs/carrack_wrapper_user/error.log

[INFO]: Calculating Runtime From the Start...

[INFO]: flow failed for carrack_wrapper/2022.02.10_17.00.33 in 0h6m12s

[INFO]: Generating Final Summary Report...

[INFO]: Design Name: carrack_wrapper

Run Directory: /openlane/designs/carrack_wrapper_user/runs/carrack_wrapper_user

Source not found.

----------------------------------------



LVS Summary:

Source: /openlane/designs/carrack_wrapper_user/runs/carrack_wrapper_user/results/lvs/carrack_wrapper.lvs_parsed.gds.log

Source not found.

----------------------------------------



Antenna Summary:

No antenna report found.

[INFO]: check full report here: /openlane/designs/carrack_wrapper_user/runs/carrack_wrapper_user/reports/final_summary_report.csv

[INFO]: Saving Runtime Environment

[ERROR]: Flow Failed.



    while executing

"try_catch $::env(OPENROAD_BIN) -exit $::env(SCRIPTS_DIR)/openroad/droute.tcl |& tee $::env(TERMINAL_OUTPUT) [index_file $::env(tritonRoute_log_file_ta..."

    (procedure "detailed_routing_tritonroute" line 6)

    invoked from within

"detailed_routing_tritonroute"

    (procedure "detailed_routing" line 13)

    invoked from within

"detailed_routing"

    (procedure "run_routing" line 54)

    invoked from within

"run_routing"

    (procedure "run_routing_step" line 10)

    invoked from within

"[lindex $step_exe 0] [lindex $step_exe 1] "

    (procedure "run_non_interactive_mode" line 43)

    invoked from within

"run_non_interactive_mode {*}$argv"

    invoked from within

"if { [info exists flags_map(-interactive)] || [info exists flags_map(-it)] } {

	puts_info "Running interactively"

	if { [info exists arg_values(-file)..."

    (file "./flow.tcl" line 356)

[maliberty]

Your pin is off the manufacturing grid:

- fastio_in[16] + NET fastio_in[16] + DIRECTION INPUT + USE SIGNAL
  + PORT
    + LAYER met2 ( -140 -2000 ) ( 140 2000 )
    + FIXED ( 122434 3193985 ) N ;

See "MANUFACTURINGGRID 0.005 ;" in your LEF. The X coordinate is not a multiple of 5.
Since the pin shape itself is illegal no valid access can be made to it.

[maliberty]

How was your pin placement generated?

[armleo]

@maliberty The DEF was generated by OpenROAD script. Interactive.py which calls io_place.tcl. All of this is in carrack_wrapper workspace.

I called place_pin w/ 329.99000 - 189.52 + 69.785 + 0.28 as X. Pin length = 4; pin_width 0.56.

How is it possible?

But thanks for debugging this. I check a couple of pins X-es and saw that they were aligned, so I assumed all of them were. My mistake. But then why OpenROAD-s generated odb is invalid? If I had to guess. Float rounding error, but still strange

[maliberty]

Your script is quite complicated and hard to follow. However 122.434 from DEF is nowhere near
puts [expr 329.99000 - 189.52 + 69.785 + 0.28]
210.535

So you must have a bug. That isn't rounding error.

[maliberty]

I think you are looking at the wrong pin:

puts [expr 241.89 - 189.52 + 69.785 + 0.28]
122.43499999999997

shows the issue. Try
set pos [expr 241.89 - 189.52 + 69.785 + 0.28]
puts [expr round($pos * 1000) / 1000.0]
122.435

[armleo]

I think it was fixed. Found the code line: https://github.com/The-OpenROAD-Project/OpenROAD/blob/9afb4fd0ca5fe8568c32aac33847211b9689800a/src/ppl/src/IOPlacer.tcl#L288

How to know if this commit made to the OpenRoad used by me?

Thanks for suggestion. I was trying to solve this for around 30 days. Absolutely insane bug 😄

Where we can put this information so other people won't encounter this issue again, and don't have to spend 30 days debugging this? My proposal: In ODB give a warning that the DEF pin is missaligned on the grid. But this warning has to wait, I still have plenty of issue to solve. Please keep this issue open. I will implement the warning myself.

[maliberty]

EDA layout tools generally use integer DBU to avoid such floating point issues (see https://github.com/The-OpenROAD-Project/OpenROAD/blob/master/docs/contrib/DatabaseMath.md).

The router has an internal check but it is more to make sure that it isn't creating such problems rather than checking user inputs. We could apply it to the user pins as a pre-check. I'll open an issue for that.

I'm not sure about your link to IOPlacer.tcl. The issue was in your or_ioplace.tcl script.

[maliberty]

The-OpenROAD-Project/OpenROAD#1634

[armleo]

@maliberty

Hi,

Issue still persists. Called:

place_pin -pin_name "wbs_sel_i[1]" -layer met2 -location [list 516.67 2.0] -pin_size [list $met2_pin_width $pin_length]

Trace log:

{place_pin -pin_name {wbs_sel_i[1]} -layer met2 -location {516.67 2.0} -pin_size {0.28 4.0}} enter

[INFO PPL-0070] Pin wbs_sel_i[1] placed at (516um, 2um).

Which results in following lines in DEF:

    - wbs_sel_i[1] + NET wbs_sel_i[1] + DIRECTION INPUT + USE SIGNAL

      + PORT

        + LAYER met2 ( -140 -2000 ) ( 140 2000 )

        + FIXED ( 516669 2000 ) N ;

Second:
Call:

{place_pin -pin_name {fastio_strong_enable[25]} -layer met2 -location {2.0 512.915} -pin_size {4 0.28}} enter

[INFO PPL-0070] Pin fastio_strong_enable[25] placed at (2um, 512um).

    - fastio_strong_enable[25] + NET fastio_strong_enable[25] + DIRECTION OUTPUT + USE SIGNAL

      + PORT

        + LAYER met2 ( -2000 -140 ) ( 2000 140 )

        + FIXED ( 2000 512914 ) N ;

Should I create an issue in OpenROAD? I am so confused why this is happening. Am I doing something wrong or a bug? I am second guessing myself.

Workaround:
Call fix_rounding_error on all numbers. It adds 0.0004 which forces it to behave correctly.

proc fix_rounding_error {num} {

    set return_value [expr round(($num) * 1000 / 5) / 200.0 + 0.0004]

    return $return_value

}

[maliberty]

I just tried

place_pin -pin_name {clk} -layer met2 -location {2.0 512.915} -pin_size {4 0.28}
write_def foo.def

and see

PINS 54 ;
    - clk + NET clk + DIRECTION INPUT + USE SIGNAL
      + PORT
        + LAYER met2 ( -2000 -140 ) ( 2000 140 )
        + FIXED ( 2000 512915 ) N ;

so I can't reproduce your issue. Please try with the latest openroad.