The Dallas '390 has a 22-bit program counter supporting access to a
maximum of 4 MB of external program memory and 4 MB of external data memory.

It also has a 10-bit stack pointer addresses up to 1kB of MOVX memory.

It also has a hardware math accelerator for 32 and 16 bit multiply and divide operations, as well as high-speed shift, normalization and accumulate
functions.

regards,
p