I have some trouble when running Openroad tools for foreign pdk.

[OuDret]

Hello, I have been reading documentation and trying stuff with given pdks for about two weeks. My goal was to run OpenRoadFlowScripts but, since there is a lot of stuff, I’ve took its makefile, config files and scripts and just extracted the openroad commands that I really need, so I can exactly know what args and what files i need and create them. Also running the commands 1 by 1 alongside GUI application helps me understanding what’s going on.

When calling the commands tho, I had some issues i could not solve. If you have an idea of any of the following problems I'm facing or any advice let me know.

1. I didn’t manage to initialize floorplan with custom die area. It doesn’t matter which values I use as die_are or core_area, it just doesn’t work properly.

When I run something like the command below, having stdSite size defined as 400 by 400 um it just does nothing. The verilog file provided is a simple inverter already synthesized using yosys into a single NAND cell which size is set in .lef as 200 by 200.

Meanwhile, if I just let openroad to decide what size to give it just works for small core utilization value, which kinda makes sense.

Do you think I’m forgetting any step? The commands I run before getting to that point are the following:

read_liberty /path/lib/NandCellLibrary.lib
read_lef /path/lef/NandCellLibrary.tech.lef
read_lef /path/lef/NandCellLibrary.macro.lef  
read_verilog /path//inverter.v
link_design inverter
read_sdc /path/constraint.sdc

initialize_floorplan -die_area {0 0 10000 10000} -core_area {1000 1000 5000 5000} -site stdSite

2. I have no macros stored in odb despite having them declared in lef/NandCellLibrary.macro.lef

If I just use utilization_area floorplan_initialization and keep running the following commands all seems to be working properly

make_tracks met1 -x_offset 10 -x_pitch 10 -y_offset 10 -y_pitch 10
make_tracks met2 -x_offset 10 -x_pitch 10 -y_offset 10 -y_pitch 10
make_tracks met3 -x_offset 10 -x_pitch 10 -y_offset 10 -y_pitch 10
remove_buffers
place_pins -hor_layer met2 -ver_layer met3 -random
global_placement -density 0.5 -pad_left 0 -pad_right 0

until I try to run macro placement

the error raised means that when running the following tcl procedure it has not found any macro

proc find_macros {} {
  set macros ""

  set db [ord::get_db]
  set block [[$db getChip] getBlock]
  foreach inst [$block getInsts] {
	set inst_master [$inst getMaster]

	# BLOCK means MACRO cells
	if { [string match [$inst_master getType] "BLOCK"] } {
  	append macros " " $inst
	}
  }
  return $macros
}

the thing is that I have the NAND macro and another one called FILL defined in my .lefs and .lib . Then why could it be that there is no macro in db ?

Some things to be said.
When running read_liberty, it prints 1 into terminal. Does it mean that there’s an error? It seems I can keep running things. If so, is there any way to properly debug it?
It also happens if I run check_status command after reading all input files, which I didn’t even find in documentation, so I just ignored it.

Again, if you had any idea or advice of what I’m doing wrong, if I skipt some important step, etc. let me know, please.

If i manage to make it work i will try to post the whole flow command by command. It may help someone someday

Thank you.

[maliberty]

What is the size of stdSite? Is this a PDK you can share or is it proprietary?

Do you have any instances of the macro in your netlist?

[OuDret]

Hello, thanks for your response

I have attached most of the pdk files. I’m not allowed to share more. Most of .lib values are placeholder taken from sky130 or nangate45. Inverter.v is the synthesized input netlist. StdSite size is 500 by 500 which is defined in .tech.lef.

pdk.zip

[maliberty]

SITE stdSite
  SYMMETRY Y ;
  CLASS CORE ;
  SIZE 500 BY 500 ;
END stdSite

is a huge site (500um x 500um) - I'm guessing that is a mistake though it doesn't explain the problem.

[OuDret]

actually the cells area for the technology I have to use is huge yet

[maliberty]

Your LEF is missing the units for " DATABASE MICRONS <val>;". There is a bug when this is unspecified that I'll fix but you should set it (the LEF default value is very old).

[OuDret]

Thank you so much, adding database units has solved it.

[OuDret]

About the other issue i was asking for help, I'd really appreciate if you could answer the following question so I have some more information to go through it and find a solution.

In the code below, where does these BLOCKs in db come from? I assumed it's from .lef file but when I run it does not find any macro, despite having defined NAND and FILL cells in .macro.lef file.

  set macros ""
  set db [ord::get_db]
  set block [[$db getChip] getBlock]
  foreach inst [$block getInsts] {
	set inst_master [$inst getMaster]

	# BLOCK means MACRO cells
	if { [string match [$inst_master getType] "BLOCK"] } {
  	append macros " " $inst
	}
  }

Thank you

[maliberty]

In LEF the "CLASS BLOCK" statement for a MACRO.