A17 on micron DDR4 ICs

[maws6502]

Hi,

Been lurking for like 7 years, finally decided to make an account hehe. I've been working on a DDR4 based design using an i.MX8M Nano UltraLite and I've been looking at the following part numbers for a 16Gbit x8 78 pin chip:

MT40A2G8JC-062E and MT40A2G8SA-062E
Links: https://www.micron.com/products/dram/ddr4-sdram/part-catalog/mt40a2g8sa-062e and https://www.micron.com/products/dram/ddr4-sdram/part-catalog/mt40a2g8jc-062e

In the datasheet for these parts (which seem to differ only in terms of overall package size, with identical footprint), ball N7 is listed as "A17/NF/NC, NF/NC", and the table below states: " A17 connection is part-number specific; Contact vendor for more information."

While I did write to the vendor, I was wondering if anyone knows if the mentioned parts of something similar (2 Gig x 8, 16GBit, 78 pin FBGA DDR4 being used in a single rank, dual chip x16 bus with fly-by routing of addr/clk/ctlr signals for 2 devices on the same side of the board) would know if the A17 pin is indeed safe to ignore, and if it isn't, where would I even connect this pin on the controller side, as I can find no reference to it in any of the i.MX8M Nano docs (Datasheet, Ref. Manual, Hardware Design Guide) or other documents (A TI document entitled "AM64x\AM243x DDR Board Design and Layout Guidelines" has proven very useful).

Additionally, I'm probably just being pedantic, but I can find no reference that states that the above part number is a single-die part other than the fact that the datasheet refers to DDP and QDPs in a way that makes it seem like these aren't either DDP or QDP, and that I can find datasheets for actual DDPs that clearly mention that they are DDP). It's probably an SDP but it'll be nice to have some reassurance.

This is the first time I've touched DRAM, so apologies if I sound a little clueless!

Thanks!