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The-OpenROAD-Project
OpenSTA hang with tristate
Description
This bug was found by @anall. This reduced test case shows the issue:
https://github.com/anall/bug-openlane_hang/tree/reduced
OpenLane hangs at step 12 trying to print clock skew report.
Environment
-
Operating System Information:
uname -aLinux matt-desktop 5.11.0-37-generic #41~20.04.2-Ubuntu SMP Fri Sep 24 09:06:38 UTC 2021 x86_64 x86_64 x86_64 GNU/Linux -
Docker Version:
docker --version
Docker version 20.10.7, build 20.10.7-0ubuntu1~20.04.2
Reproduction Material
- Upload a tarball containing the relevant design - see repo linked above
- List the commands used to run the design:
- cd $OPENLANE_ROOT; make mount; ./flow.tcl -design bug-openlane_hang
Expected behavior
The flow to finish.
Logs
Last lines printed before hanging.
Startpoint: we (input port clocked by clk)
Endpoint: data (output port clocked by clk)
Path Group: clk
Path Type: max
Fanout Cap Slew Delay Time Description
-----------------------------------------------------------------------------
0.00 0.00 0.00 clock clk (rise edge)
0.00 0.00 clock network delay (ideal)
2.00 2.00 ^ input external delay
0.02 0.00 2.00 ^ we (in)
1 0.00 we (net)
0.02 0.00 2.00 ^ input3/A (sky130_fd_sc_hd__buf_1)
0.09 0.11 2.11 ^ input3/X (sky130_fd_sc_hd__buf_1)
1 0.01 net3 (net)
0.09 0.00 2.11 ^ _04_/A (sky130_fd_sc_hd__inv_2)
0.02 0.04 2.15 v _04_/Y (sky130_fd_sc_hd__inv_2)
1 0.00 _03_ (net)
0.02 0.00 2.15 v _09_/TE_B (sky130_fd_sc_hd__ebufn_1)
0.10 0.10 2.25 ^ _09_/Z (sky130_fd_sc_hd__ebufn_1)
1 0.01 data_c (net)
0.10 0.00 2.25 ^ _08_/A (sky130_fd_sc_hd__ebufn_4)
0.18 0.23 2.48 ^ _08_/Z (sky130_fd_sc_hd__ebufn_4)
2 0.02 data (net)
0.18 0.00 2.48 ^ data (inout)
0 0.02 data (net)
2.48 data arrival time
0.00 10.00 10.00 clock clk (rise edge)
0.00 10.00 clock network delay (ideal)
0.00 10.00 clock reconvergence pessimism
-2.00 8.00 output external delay
8.00 data required time
-----------------------------------------------------------------------------
8.00 data required time
-2.48 data arrival time
-----------------------------------------------------------------------------
5.52 slack (MET)
min_max_report_end
clock_skew_report
[INFO CTS-0001] Running TritonCTS with user-specified clock roots: clk. [INFO CTS-0095] Net "clk" found. [WARNING CTS-0041] Net "clk" has 1 sinks. Skipping... [WARNING CTS-0083] No clock nets have been found. [INFO CTS-0008] TritonCTS found 0 clock nets. [WARNING CTS-0082] No valid clock nets in the design. [INFO]: Repairing long wires on clock nets...
Is that WARNINGS cause the problem?
Here is the whole design: https://github.com/anall/sudoku-accelerator/tree/97e77a088f2bb9ecb7a40e3fa11b96c1ba332264 And this is the CTS log, where it shows it does identify the clock and makes a clock tree.
Here is the whole design: https://github.com/anall/sudoku-accelerator/tree/97e77a088f2bb9ecb7a40e3fa11b96c1ba332264 And this is the CTS log, where it shows it does identify the clock and makes a clock tree.
@mattvenn with suduku_puzzle design I'm able to complete the flow without any issue using openlane tag 2021.11.17_01.42.05.
Following up on our slack conversation: You need to be using that specific commit -- I've already changed my design to work around this bug.
Alternatively, here's the folder from designs/ with the relevant files already checked out
sudoku_puzzle_bug.tar.gz
This is working now with latest OpenLane. Please reopen if there is still and issue.
