Sorry, I meant datasheet for how to build a programmer. There
is some sort of serial protocol.
Well, for PICs, there are a variety of techniques to handle --
that is, if you want to actually design your own general purpose
programmer. For example, one technique for the 16C5x series
(the oldest type made available for hobbyist use, I think) and
an entirely different approach for the PIC18's and an entirely
different approach for the 16C84. And at least a few other ones
in between.
As to data sheets on how, there is AN589. But that only applies
to the 16C84. There's AN750, on a PIC18C. There are guides on
in-circuit programming (30277c, for example, and TB016 as well.)
I believe some of the early paper application notes provide
example circuits, as well. Anyway, look around. You might find
schematics in the user manuals, programming specifications, and
out on the web.
And do look on the web for programmer schematics for PICs.
There are several good ones out there. Or make your question
more specific, because I don't think there is a single,
comprehensive, one-stop shopping place for a datasheet on
building programmers for the breadth of available PICs. But I
could be wrong.
Jon