On Tue, 15 Dec 1998, Regulus Berdin wrote:

> Hi Adriano,
>
> This can be done also by (2 code space less):
>
>pow10   movwf   rD
>         addwf   rD,w    ;rD*2
>         addwf   PCL,f
> p0      clrf    rC
>         retlw   0x01
> p1      clrf    rC
>         retlw   0x0A
> p2      clrf    rC
>         retlw   0x64
> p3      movwf   rC      ; W=3
>         retlw   0xE8
> p4      movlw   0x27
>         movwf   rC
>         nop
>         retlw   0x10


I saw  that too, BUT isochronicity (is that a word?) is lost. Also,
there's a small error with case p3 (W is 6 not 3 when it is stored into
rC).. But if you're willing to sacrifice isochronicity the you might as
well get rid of the nop:

pow10   movwf   rC
        addwf   rC,w    ;rC*2
        addwf   PCL,f
p0      clrf    rC
        retlw   0x01
p1      clrf    rC
        retlw   0x0A
p2      clrf    rC
        retlw   0x64
p3      nop             ;rC is 3
        retlw   0xE8
p4      movlw   0x27
        movwf   rC
        retlw   0x10



  call   pow10
  movwf  rD


But it takes 11 cycles for the 4th power (as opposed to 10 for Adriano's
solution)