Can someone help me with the following error? I am not using vccd2 domain in my design.

[WARNING PSM-0038] Unconnected PDN node on net vccd2 at location (1107.000um, 1252.295um), layer: 5.
[ERROR]: PDN generation failed.
[ERROR]: You may need to adjust your macro placements or PDN  offsets/pitches to power all standard cell rails (or other PDN stripes)  in your design.

Hi @User, I had the same problem, the issue is that Your macro PDN network has to be aligned with the user_project_wrapper PDN

Interesting. And how can I align? Incrementally make shifts until they're decently aligned and the error goes away? For example, shifting the macro up by approx 30um?

here You have for example 2 rings, could be GND and VDD, so on the metal 4 and 5 you have this vertical and horizontal strips which distribute the energy to the cells. What happens is when You prepare Your macro You should have the same pitch (spacing between strips) and also place it in the wrapper space in a spot where they align

Are you talking about the following? Which one's the pitch and which one's the offset. Using klayout I see that the pitch is around 90um. Not sure what offset means.. set ::env(FP_PDN_VWIDTH) 3.1 set ::env(FP_PDN_HWIDTH) 3.1 set ::env(FP_PDN_VSPACING) [expr 5*$::env(FP_PDN_CORE_RING_VWIDTH)] set ::env(FP_PDN_HSPACING) [expr 5*$::env(FP_PDN_CORE_RING_HWIDTH)]

VSpacing, HSpacing

Got it. Thanks a lot..

👍

Honestly, this should be reported as a bug in the caravel_user_project repository github issue tracker. There is no reason in the world why the user project must have a PDN aligned with anything other than the outside rings. To require the same pitch is patently stupid.

@User in fact I taught i was solved in the recent versions of the flow. I had this situation late September working on MPW3. By the way do You know why in MPW5 and MP6 the detailed router is way more memory demanding, the Tritonroute was upgraded or there was change in the flow ?

Well, for me the issue was fixed after trying another set of coordinates for the macros; I did not specifically try to align the stripes because I did not need to. So I am not sure what exactly triggers this error.

i've seen pitch alignment issues only on very small macros

Hi @User, in fact there are two issues: (1) open lane generates unaligned PDN form small macros, (2) there was a problem (and seems to exists today) with a mechanism of macro placement and legalization of its position to be aligned with the wrapper's PDN.

I used to get placement issues but related to alignment of the routing grid