@User: That shouldn't be necessary, though. There are no straps in the wrapper, just the rings. The user project should be able to use any pitch it wants for the M4 and M5 power straps.

Hi @Tim Edwards, I am not quite sure what you mean. I am following the description regarding the PDN here: https://openlane-docs.readthedocs.io/en/rtd-develop/doc/advanced_power_grid_control.html This is how

user_project_wrapper

looks like (just showing M4 and M5, full view and zoom in of there my macro is placed). You can see the H/V grid in M4 and M5, plus the “extra” M4 V-strips which are put there when the macro is hardened. This also fits the PDN generating code in `pdn_cfg.tcl`:

if { $::env(DESIGN_IS_CORE) == 1 } {
    # Used if the design is the core of the chip
    define_pdn_grid -name stdcell_grid -starts_with POWER -voltage_domain CORE -pins [subst {$::env(FP_PDN_LOWER_LAYER) $::env(FP_PDN_UPPER_LAYER)}]
    add_pdn_stripe -grid stdcell_grid -layer $::env(FP_PDN_LOWER_LAYER) -width $::env(FP_PDN_VWIDTH) -pitch $::env(FP_PDN_VPITCH) -offset $::env(FP_PDN_VOFFSET) -starts_with POWER
    add_pdn_stripe -grid stdcell_grid -layer $::env(FP_PDN_UPPER_LAYER) -width $::env(FP_PDN_HWIDTH) -pitch $::env(FP_PDN_HPITCH) -offset $::env(FP_PDN_HOFFSET) -starts_with POWER
    add_pdn_connect -grid stdcell_grid -layers [subst {$::env(FP_PDN_LOWER_LAYER) $::env(FP_PDN_UPPER_LAYER)}]
} else {
    # Used if the design is a macro in the core
    define_pdn_grid -name stdcell_grid -starts_with POWER -voltage_domain CORE -pins $::env(FP_PDN_LOWER_LAYER)
    add_pdn_stripe -grid stdcell_grid -layer $::env(FP_PDN_LOWER_LAYER) -width $::env(FP_PDN_VWIDTH) -pitch $::env(FP_PDN_VPITCH) -offset $::env(FP_PDN_VOFFSET) -starts_with POWER
}

@Harald Pretl: This is wrong. The project should be placed in a layout

user_project_wrapper_empty

which has no pre-existing straps. The straps are generated and placed by openlane. @Manar Abdelatty: What happened to the empty project wrapper???

Sorry for the confusion, I think I expressed myself not clearly enough: What I sent above was the result after hardening the user project in the wrapper. I have not checked how the

user_project_wrapper_empty

looks like. The hardening of the user project in OpenLane adds the M4-V straps to the user project, and the following hardening of the project wrapper adds the M5-H and the M4-V straps, having now M4-V straps of both steps. This is what causes issues when the two sets of M4-V straps are not properly aligned.

@Harald Pretl: No, I understand what your issue is. But something is broken with the system, because that's not how it is supposed to work. There should be a completely empty wrapper with no straps in it. The user project is dropped into it, and there should be no conflicts like what you're seeing. That layout was called

user_project_wrapper_empty

and it appears that it no longer exists in any repository, or at least I can't find it. I think the openlane developers may have replaced the

_empty

wrapper layer with the "standard" one but failed to use the right layout for it.

Got. I wait for guidance how to resolve this correctly. 🙂

Possibly Manar is not available now. @Marwan Abbas: Can you please take a look at this?

I just had a look in GitHub,

caravel_user_project

. Here in the

user_project_wrapper.gds

the vertical power straps are nicely cut out around the user macro.

The problem is being looked into.

So it looks like it depends on the versions used. I am using these, could you please propose a better/newer config?

@Harald Pretl Hello, sorry for the late reply. versions tested: OpenLane tag:

2021.09.19_20.25.16

Caravel tag:

mpw-4b

Caravel-lite tag:

mpw-3

caravel_user_project tag:

mpw-3

open_pdks:

6c05bc48dc88784f9d98b89d6791cdfd91526676

this works, but only as long as one does NOT set

CARAVEL_LITE=0

… then there is an issue in Git which I can’t resolve.

@Harald Pretl I can't replicate your issue, what commands are you using?

@Marwan Abbas I use this:

export STD_CELL_LIBRARY=sky130_fd_sc_hd
export CARAVEL_ENV_ROOT="$HOME/test/caravel_env"
export PDK_ROOT="$CARAVEL_ENV_ROOT/pdk"
export OPENLANE_ROOT="$CARAVEL_ENV_ROOT/openlane"
export CARAVEL_ROOT="$CARAVEL_ENV_ROOT/caravel_user_project/caravel"
export PRECHECK_ROOT="$CARAVEL_ENV_ROOT/precheck"
export CARAVEL_LITE=0
export CARAVEL_USER_PROJECT_COMMIT=mpw-3
export CARAVEL_COMMIT=mpw-4b
export OPEN_PDKS_COMMIT=6c05bc48dc88784f9d98b89d6791cdfd91526676
export OPENLANE_TAG=2021.09.19_20.25.16

with this:

git clone <https://github.com/efabless/caravel_user_project.git>
cd caravel_user_project || exit
git checkout $CARAVEL_USER_PROJECT_COMMIT
make install
cd caravel || exit
git checkout $CARAVEL_COMMIT
cd ..
make pdk
make openlane
make precheck

and the error is this:

HEAD is now at fc583ec Auto updated submodule references
Installing caravel as a submodule..
Submodule 'caravel-lite' (<https://github.com/efabless/caravel-lite>) registered for path 'caravel'
Cloning into '/home/harald/test/caravel_env/caravel_user_project/caravel'...
Submodule path 'caravel': checked out '0f16ba8eaae841a6f122fc0d5837005d3312fd2b'
error: pathspec 'master' did not match any file(s) known to git
make: *** [Makefile:80: install] Error 1