> At 21:58 24.03.97 -0600, you wrote:
> >> > > Puzzle N2>   Is required to load any file REGister with value = VALUE ,
> >> > > but W register haven't be changed after load is over .
> >> >
> >> > MOVWF reg
> >> > XORLW VALUE
> >> > XORWF reg,f
> >> > XORWF reg,W
> >> I've another similar solution...
> >>
> >> XORLW VALUE
> >> MOVWF REG
> >> XORLW VALUE
> >> XORWF REG,F
> >
> >Depending upon /Value/, it may be possible to do the job in 1 to 5 cycles
> >without altering W _or_ the flags (useful perhaps in an ISR, since saving
> >context is such a pain).  If the old value in the f-register is known, then
> >any change may be done in 0 to 4 cycles (zero of course being if you want to
> >"change" the register to its existing value).
> >
> >Here are some of the ways of setting a register in very few instructions:
> >
> >[1] Set to zero: the obvious one...
> >        clrf    reg
>
> Doesn't CLRF alter the Z-flag?!

I thought [perhaps I need to get out my book] that clrf only affected the Z
flag on the 17Cxx parts.  Hmm... I'll have to double-check that.

> >[2] Set to a power of two.  Also pretty obvious...
> >        clrf    reg
> >        bsf     reg,bit
> >
> >[3] Set to 255.  Still pretty obvious, but for one slight detail...
> >        clrf    reg
> >        decfsz  reg     ; Note: next instruction will NEVER be skipped.
>
> Don't we have SETF reg ? (Perhaps only 17Cxxx)

Not on any of the 16Cxx devices.

> regards,
>
> Wolfram

Hmm... would be embarassing if I'm wrong on /clrf/.