I try to harden an analog IP macro with digital parts. Using

flow.tcl

all steps work correctly, except last (STEP 35 LVS). There are the power pin that are not connected. Why? The verilog netlist is correct:

Looking at

pdn_cfg.tcl

it seems OpenLane connects macros over

met5

-

met4

by default. If you want connections

met4

-

met1

to the macro then I'd try copying

pdn_cfg.tcl

to the design folder, set the new path

"PDN_CFG": "dir::pdn_cfg.tcl",

in

config.json

and add line

add_pdn_connect -grid macro -layers "met1 met4"

to

pdn_cfg.tcl

. If LVS passes, don't trust the result blindly, doublecheck the

gds

if everything is tied up correctly (the lower two power rails might never be connected due to distance rules, but technically GND always finds a connection over substrate)

@User, I try this solution but VDD and GND are not connected ...

What about the upper two rails not shown in the screenshot? They should be connected at least

No, the upper two rails are not connected because the VDD and GND port in lef file are on the left. I change it with

lef write -hide

I see, do you want them to be on the left? Because, power is just not connected the same way as signals. Power with the intention to connect to the vertical metal4-PDN will need horizontal rails in the

lef

with explicit

port

definition (pin layer in the lef), long enough to touch at least 2 rails of the vertical PDN. Don't know what

-hide

does to the obstruction layers between metal1 and metal4 btw. but there's a possibility this might prevent a connection down to metal1 rails. Suggestion: The "cleanest" solution (since you are hardening a macro inside a macro) might be to restrict the PLL macro to use only layers up to metal3 (if possible) and then add

VDD

and

GND

power rails going horizontally all over the macro on metal3 with explicit

port

definition. Documentation on power grid control: https://github.com/The-OpenROAD-Project/OpenLane/blob/master/docs/source/usage/advanced_power_grid_control.md

Thank you very much for your detailed explanation. I change my layout and now flow complete succesfully!