Where can I obtain the datasheet or manual for the Hitachi HD63140
Universal Pulse Processor chip for a reasonable cost (less than $40)?

I am looking for documentation about this IC. Ideally I would want
information on how to program it and information about the pinouts of
the 68-pin PLCC version (called HD63140CP), in PDF form at no cost,
but I would settle for just the programming information as a hard copy
at low cost.

From what I understand, this chip was designed to be paired with an
HD6303-series microprocessor. It provided ADCs, pulse-width-modulated
outputs, a watchdog timer, some static RAM, and maybe a few other
things.

Hitachi started producing this chip sometime in the mid to late 1980s.
At some point Hitachi sold their semiconductor business to Renesas.

Apparently there was at least one relevant publication from Hitachi
aside from the datasheet: Application note ADE-202-015A, "HD63140
universal pulse processor," published in 1988.

I have considered the possibility that some libraries, particularly at
some universities, may have the original datasheet but I don't know
where to begin searching. Datasheets, both obsolete and current, are
generally freely distributable but I haven't found this particular one
in any online repositories thus far.

Try http://www.microrobotics.co.uk/docs/pdf/44070.pdf

it may be some help if not much

To the person who posted a comment earlier about having access to a
physical copy of the datasheets:

I posted a reply, and apparently the Google Answers editors saw fit to
delete both your message and mine.

I have posted this question again so that if you are a researcher you
can submit an answer. It is in the Science > Technology category.
Thank you.