What, exactly, do you mean by that?

Have you exhaustively tested over all possible operating conditions and all scenarios - thoroughly measuring all parameters and confirming that they are within specifications?

Or have you just tried it in just one IC, and not noticed any issues?

If all you've done is just tried it in just one IC, and not noticed any issues, then it is entirely possible that your code (and/or hardware) has latent bugs that just don't happen to show up in the limited contitions under which you've tried it.


In what way(s), exactly, is it not "correct"?

Software doesn't work in an IC alone; you also need external hardware - so you might (also) have (a) hardware issue(s)...

Again, how thoroughly have you really tested (not just "tried") it?


The most likely is that you are relying upon some thing - or things - that differ between the two ICs, and/or are present in one but not the other.

In particular, look out for registers which have some bits used in one chip but not the other:

If you write to an unused bit in one chip, that might not cause an issue; but, if the other chip does use that bit, there could be an issue;

If you don't properly mask-out an unused bit when you read a register in one chip, that might not cause an issue; but, if the other chip does use that bit, there could be an issue;

etc,...


It'll take more than a quick read.

You will need to go through the two datasheets, side-by-side, with a fine-toothed comb very carefully checking for every difference.



Then you're going to have to debug it yourself!

http://www.8052.com/faqs/120313