M9K Resource in SOPCB

The memory array need not be complete.

Your 27k block can easily be made of seven 32bit x 1k blocks (28 M9K blocks).

Since a single M9K can be be configured as 256 32bit words (or 36bit) it is also (probably) possible) to only use 27 M9K blocks - but with additional logic.

My guess is that a full 32k bytes uses less logic and 28k.

When you increase the second memory area over 10k, the additional pressure on M9K blocks changes the way the first block is allocated.