I have managed to get some PIC17C44 parts.
I thought that code for PIC17C42A should run unchanged on the PIC17C44.
I re-compiled the code for PIC17C44 changing:
- Code: Select all
list p=17c42a
include <P17c42a.inc>
to
- Code: Select all
list p=17c44
include <P17c44.inc>
and the output hex file was identical.
However when I programmed a 17C44 it didn't work It's possible of course that the chip was bad, but I'm loath to burn more of these OTP parts as I only have a limited stock.
I've spent a long time looking at the datasheet and don't understand why it didn't, because unless I missed something the pin-out is identical. Are there some crucial parts of the memory map (e.g. interrupt vectors) that are different?
Can someone who knows these parts better than I give me some guidance.