...and (I know you're not the guy to bust on this but)...
This (from the C5515 datasheet) is also confusing and somewhat misleading:
320K Bytes Zero-Wait State On-Chip RAM,
Composed of:
– 64K Bytes of Dual-Access RAM (DARAM),
8 Blocks of 4K x 16-Bit
– 256K Bytes of Single-Access RAM (SARAM),
32 Blocks of 4K x 16-Bit
Once you actually do the math you realize that you really only have half of this amount of RAM.