pdgen remove stripes with [WARNING PDN-0200] Removing floating shape:

Tool: Power Distribution Network Generator

Subcategory: Power distribution network issue

Conversation

titan73

Based on the example at the bottom of https://openroad.readthedocs.io/en/latest/main/src/pdn/README.html.

I did the following floorplan with the .def containing the power pins:

read_def -floorplan_initialize floor.def
set fp_area [ord::get_die_area]
initialize_floorplan -die_area $fp_area -core_area $fp_area -site CORECUBRICK

add_global_connection -net VDDD -pin_pattern {^VDDD$} -power
add_global_connection -net GNDD -pin_pattern {^GNDD$} -ground

set_voltage_domain -power VDDD -ground GNDD

define_pdn_grid -name "Core"
add_pdn_ring -grid "Core" -layers {metal4B alucap} -widths 5.0 -spacings 2.0 -core_offsets 4.5 -connect_to_pads

add_pdn_stripe -followpins -layer metal1 -extend_to_core_ring

add_pdn_stripe -layer metal4B -width 0.48 -pitch 56.0 -offset 2.0 -extend_to_core_ring
add_pdn_stripe -layer alucap -width 1.40 -pitch 40.0 -offset 2.0 -extend_to_core_ring

add_pdn_connect -layers {metal4B alucap}
add_pdn_connect -layers {alucap metal4B}

pdngen

The sroutes and the ring are created but not the stripes and I get the the warnings:

[WARNING PDN-0200] Removing floating shape: GNDD (1.7600, -9.5000) - (2.2400, 821.3000) on metal4B
[WARNING PDN-0200] Removing floating shape: VDDD (29.7600, -16.5000) - (30.2400, 828.3000) on metal4B

Is there something more to do to connect these shapes?

titan73

Also note that the related power pins imported the from .def are removed.

maliberty

Can you provide a test case? Its hard to say much from just the output