PL power pins and RSVDGND pin on XC7Z030

[gooryl]

Dear community, 

I am working with XC7Z030 and I have to questions:
1) Technical reference manual says that power supplies for PL and PS part are fully independent, but does this mean, that if I do not use PL part, it’s power pins can be left floating?

2) Technical reference manual says that RSVDGND must be tied to ground (page 59), but on the other hand packaging and pinout product specification points that this pin must not be connected to anything (page 13). Here is the links for this documents:
TRM        https://www.xilinx.com/support/documentation/user_guides/ug585-Zynq-7000-TRM.pdf
PkgPinout https://www.xilinx.com/support/documentation/user_guides/ug865-Zynq-7000-Pkg-Pinout.pdf

I see, that Technical reference provides information on page 59 only for 7z007s and 7z010 Device, but my mentor wants to be sure about this pin.

Thank you in advance.

[tenzinc · Accepted solution]

Gooryl,

1) Yeah, kind of... PL is not as independent as it sounds. It is reliant on PS to boot. If you intend on not using the PL ever, you can* leave the supply pins floating BUT I recommend trying them to a known reference plane/potential. Leaving them floating reduces the level of ESD protection on the supply pins and the associated IO pins supplied by them. Also if you are trying to reduce device power without having to sacrifice the PL you can control the PL rails through software from the PS such that when the PL is not needed it can be shut down and powered back on when called upon. See WP404 and UG933 for more details. 

2) Leave it floating if you can. Package guide is much newer and updated. See https://www.xilinx.com/support/answers/70537.html from where the floating recommendation comes from. 

Regards,

T