piclist 2003\02\16\223025a >
Thread: Stupid newbie PIC question
face BY : Ned Konz email (remove spam text)

On Sunday 16 February 2003 06:54 pm, Dave Dilatush wrote:
> David Duffy wrote...
> >Cool - I hate the register banks. Gonna have to get some 18Fxx
> >devices to play with soon I think.
> No program memory paging, either.  Multiple FSR/INDF registers.
> No more retlw tables.  40 MHz speed.

And a bug with calling across the 0x4000 boundary, too (that I just
heard about) (see the PIC18FXX2 Rev. B3/B4 Silicon/Data Sheet
Errata). Work-arounds exist, though:
Two possible solutions are presented. Others may exist. It is
recommended to implement either or both as needed. 1. Insert a data
word of value FFFFh as the first instruction in the destination of a
CALL or GOTO. 2. Insert a data word of value FFFFh immediately
following any RETURN, RETLW, or RETFIE instruction.

However, I don't know whether any of the compilers I have (the CCS PCH
and Microchip C18) deal with this problem.

Still, they *are* nice chips compared to the 14-bitters.

You can also read the top of stack (!).

Note that there *is* still RAM banking.

It's hard to justify using a 16F877 (for instance) when you can get an
18F442 (with twice the RAM and program space) for less money.

Ned Konz

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