Hi,
This January Microchip released an revised errata for
the 18Fxx2 series of chips, and in this there are some disturbing
problems mentioned.=20

Particulary refering to 18F452, the errata states that an table read,
call, goto, return, retlw or retfie crossing the 0x4000 program boundary
can,=20
and I paraphrase, "Under certain conditions.....may yield unxpected
results".=20
Now there are no further explanations part from the suggested 'fix' to
put=20
0xFFFF as the first instruction after CALL or GOTO, OR insert 0xFFFF=20
immediately following RETURN, RETLW or RETFIE.
It's also recommended to add either or both "as needed" ??? when do I
need
to add both ?

Now, even though I understand the factual information , I am a bit
perplexed by this
bug, I do use 18F452 and have tables and/or calls that operates across
the 0x4000
program boundary. I have not added the suggested fix but still I have
not surfaced any
problems (yet).Have I just been lucky ?=20
does anyone have more information about the specifics when these errors
surface ?=20

Yes I know, short answer, just add the 0xFFFF all other the place, but
I'm reluctant to
do so, I already have quite a few conditionals to cater to various bugs,
adding additional
ones is starting to get me very wary aginst using these chips at all.=20

Particulary as when using the linker, normally you do not have full
control in which segment
an particular routines and/or table is placed. Not crossing 0x4000
boundary is a tricky beast
to handle with the linker.

Can anyone enlighten me more than the errata ?

/Tony

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