The Power Delivery Network is what provides power for all the macros in your design.

For the shuttle, LibreLane creates a PDN that supplies the 4 rails available to the user project area:

inout vdda1,    // User area 1 3.3V supply
inout vdda2,    // User area 2 3.3V supply
inout vssa1,    // User area 1 analog ground
inout vssa2,    // User area 2 analog ground
inout vccd1,    // User area 1 1.8V supply
inout vccd2,    // User area 2 1.8v supply
inout vssd1,    // User area 1 digital ground
inout vssd2,    // User area 2 digital ground

Metal 4 is used for vertical lines that are cut for the macros, and Metal 5 routes over the top of everything. When the metal 5 lines pass over the macro, vias are dropped to connect the macro’s internal PDN to the user project area’s PDN.

A common failure for small designs with the LibreLane tools is that there isn’t enough area for the PDN to get created. A simple fix is setting the absolute size of the die to make sure its large enough.

Course feedback

I love the layout of the course, you did a perfect job Matt. Building up the foundation and then getting into the depths of it. Having everything lined up. I love the walkthroughs at the end of each section. I did the work and then I looked back, maybe there's a better way and in your videos you point out some other interesting things as well so that was really helpful. So yes I love the course.

Konrad Wilk (digital course)