On Sun, 7 Dec 1997 06:45:21 EST NCSProduct <NCSProduct@AOL.COM> writes:
>Is the 16F84 a drop-in replacement for the 16C84?
>
>That is to say, I am currently using 16C84's in a product,
>programming them with a PIC16Cxx-PGM from Parallax,
>and using the Parallax assembler.
>
>I want to know if I can switch to 16F84 without updating my
>programmer or assembler..

Generally the F84 programs the same as the C84, but the Power-up Timer
fuse is opposite in polarity.  Also the Code-Protect is done differently.
 If you don't enable the Code Protect, and set the Power-up Timer to
'off' when it's supposed to be on, then the C84 programmer can program
the F84.

Both chips use the 14-bit core and same special function registers, so
the same object code will work in either.  But 32 of the file registers
(0x30 to 0X4F) that were unused in the C84 are now live RAM in the F84.
Unless the program is expecting these locations to read 0, a C84 program
will just not use them, so it will work OK in a F84.   Depending on how
thoroughly the assembler checks the RAM allocations, it may not be
possible to use the C84 mode to assemble a program that uses the extra
RAM in the F84.