I found FRAM useful because it not only works byte-by-byte, without any paged organization, but also writes as fast as it reads, which, for the most part, is as fast as RAM. It requires no delay loops, no waits (not that the 805x has 'em, but I did find ways to make them work when needed, along with the associated caveats) and they don't have specific brownout behaviors as do the BBRAMs ... AND there's no limit on now many times you write a particular location, so you can use it as scratchpad without worrying about the write cycle limit.

Yes, the ones I used come in TSOP's and therefore require large, though not tall, unwieldy adapters if you use them with wire-wrap, as I often do, but they're pretty handy!

Remapping external code and data memory into a single monolithic space, albeit only 64kB in size, simply requires a 74HC11.

RE