piclist 1998\10\26\224506a >
Thread: Picn up the Pace Q2
face BY : paulb@EraseMEmidcoast.com.au

Heinz Czychun wrote:

> On the 16F84s the second bank of registers are accessable by setting
> the rp0 bit in the status register.  This allows the Option, and
> Trisx registers to be accessed directly.  Thus making the TRIS, and
> OPTION instructions obsolete.

 Hey!  Whoa there!  I wouldn't say that's true *at all*!!!  Having TRIS
and OPTION registers accessible as such is only useful in terms of
performing reads on them, and by implication, Read-Modify-Write or so-
called "bit" set/ clear functions which are by common assent, just a bit
dicky anyway.

 As I see it, the combination "movlw value; tris portb" is an awful lot
better than "movlw value; bsf status, rp0; movwf portb; bcf status, rp0"
but of course, maybe others see it differently.

> These are still supported by the 'F84 but, presumably can become
> unsupported in the future.

 Presumably, but obviously can *not* become unsupported in the 16F84.

 It's all really a rather amusing pretension to code-transportability
in an environment where code transportability isn't particularly
       Paul B.

<36354179.275C@midcoast.com.au> 7bit

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