Hey guys, do you have any tips on dealing with rou...
# openlanej
Jure Vreča
03/17/2022, 4:07 PMHey guys, do you have any tips on dealing with routing congestion problems? I am attaching the error I am getting. As a bit of context I am trying to harden a very simple SoC, which consists of 2 1-kbyte SRAM blocks and a simple risc-v core. I am also attaching the config.tcl file. Any help is appreciated.
m
Matt Venn
03/17/2022, 4:31 PMcan you show the floorplan?
j
Jure Vreča
03/17/2022, 4:40 PMI am attaching the run directory.
m
Matt Venn
03/17/2022, 4:43 PMhow are you placing the macros?
Matt Venn
03/17/2022, 4:43 PMI can't see from the run
Matt Venn
03/17/2022, 4:43 PMmacro.cfg doesn't seem to get included
Matt Venn
03/17/2022, 4:44 PMthis is the pdn
Matt Venn
03/17/2022, 4:44 PMimage.png
Matt Venn
03/17/2022, 4:44 PMbut I don't see where the 2 sram would go
Matt Venn
03/17/2022, 4:44 PManother thing to konw is that you can't put sram inside your project, they have to be on the top level
j
Jure Vreča
03/17/2022, 4:44 PMI am not placing them, I thought they will be placed automatically
m
Matt Venn
03/17/2022, 4:44 PMthis is due to limitations in the PDN
Matt Venn
03/17/2022, 4:44 PMno they won't get placed
j
Jure Vreča
03/17/2022, 4:44 PMah. So i have to put it in the user_project_wrapper?
m
Matt Venn
03/17/2022, 4:45 PMso you are just trying to harden the riscv cpu here?
j
Jure Vreča
03/17/2022, 4:45 PMno
Jure Vreča
03/17/2022, 4:45 PMI was trying to harden the cpu and also add the srams
Jure Vreča
03/17/2022, 4:47 PMI don't understand the reason for why they are two folders: user_proj_example and user_project_wrapper. Is it ok if I just delete the user_proj_example and move everything too user_project_wrapper?
m
Matt Venn
03/17/2022, 4:47 PMuser_proj_example is a dmeo project
Matt Venn
03/17/2022, 4:47 PMyou can use it as a template
Matt Venn
03/17/2022, 4:48 PMyou can't put anything in user_project_wrapper that needs to be synthesised, only already hardened macros
j
Jure Vreča
03/17/2022, 4:48 PMah
m
Matt Venn
03/17/2022, 4:48 PMso you need to harden your riscv as one block, then connect it up to 2 sram blocks in user project wrapper
j
Jure Vreča
03/17/2022, 4:48 PMso I should put the risc-v core in the user_project_example and put the sram in the wrapper
Jure Vreča
03/17/2022, 4:48 PMI see, Thank you for that info. Ill try that now.
m
Matt Venn
03/17/2022, 4:50 PMif you are new to the tools, I might advise you to simplify your goal
Matt Venn
03/17/2022, 4:51 PMhere's my application that uses sram
Matt Venn
03/17/2022, 4:51 PMMatt Venn
03/17/2022, 4:51 PMand there are lots of workarounds to get it to work, including turning off drc checking and obstruction layers
j
Jure Vreča
03/19/2022, 12:29 PMHey Matt, sorry the reply is so late, I was traveling yesterday and didn't find the time to try your advice out. But today I did, and I separated the risc-v core in to a the user_project_example. This fixed the original routing problem, but the router now still fails to complete, and the error is not very descriptive. I am attaching a picture of the error as well as the issue reproducible zip. Also the github link: https://github.com/jurevreca12/rvj1-caravel-soc/ , contains the latest design. I will be very grateful for any help.
Jure Vreča
03/19/2022, 12:32 PMI am also attaching the lower part of the error output.
Jure Vreča
03/19/2022, 12:32 PMimage.png
Jure Vreča
03/19/2022, 4:19 PMAfter some googling I realized that the issue I am having is the same as https://github.com/The-OpenROAD-Project/OpenLane/issues/996 . After updating my openlane version, I get the same stack trace output as in the git link.
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