Nathan House <nathanpiclist@gmail.com> writes:
> I'm learning to program a PIC18 using assembly language and am curious
> why there seems to be some redundancy with many instructions. Take the
> MOVF instruction, for example:
>
> MOVLB 0x2          ;select bank 2
> MOVF   0x240, W  ;move the value at 0x240 to W
>
> If my understanding is correct, then the "2" digit in the MOVF
> instruction is ignored completely, making it redundant since the bank
> is selected above. From what I've read, it seems that the assembler
> automatically sets the access "a" bit based on the address when
> translating to machine code, so what I'm wondering is why the
> assembler doesn't automatically generate bank select instructions as
> well?

Well, if you access several locations in the same bank in a row, you
only need to use one MOVLB (or BANKSEL) command. Emitting one before
each access would halve the speed at which your program ran...

Rupert

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