7730 addressing question

[Ludis Langens]

dhardin at ovec.com wrote:
> 
> Got a question.....not a critical one, .....I'm hacking a v6 730 eprom and
> I noticed some jump instructions to an address range outside the Eprom
> around $5100.
> My question is:  are
> they running the 68hc11 in a mode where it has some internal subroutines
> and memory,  or is somewhere else in the program some subroutines being
> written into this space and then executed.   Has anyone seen this before?

They are invoking test functions in a test PROM which of course is not
hooked up in productions systems.  You will notice that all JMPs/JSRs to
the $5xxx range are protected by a flag test of some sort.

-- 
Ludis Langens                               ludis (at) cruzers (dot) com
Mac, Fiero, & engine controller goodies:  http://www.cruzers.com/~ludis/