Have anyone designed a one pin interface?

It would be nice to have a simple monitor suopport program in every PIC, so
if we want to check inside it when it is working (or working wrong) we can
attach a specialised unit with a display and keyboard to it. We must use
minimum number of pins for it (one), and it should be possible to implement
"everywhere".

The monitor unit I believe can be built using a F84, LCD and a few keys to
select adress and view and change registers, force gotos or calls to
stop,test,run routines etc in the target system.

The target system«s routine shoud of course be as possible as possible, and
perform som kind of erroer check so it don«t treat noise as instructions.

The monitor scans the keys, decode it to simple instructions and send them
to the target. The target sends back register contents binary, which the
monitor decodes and displays.

/Morgan O




Morgan Olsson, MORGANS REGLERTEKNIK, Sweden, ph: +46 (0)414 70741; fax 70331
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