On 11 Mar 2015 at 23:16, Josh Koffman wrote:

> Hi all,
>=20
> I've seen a few different ways to do this, and I'm not sure if there
> are better or worse ways on this one. I am working in XC8, and I want
> to be able to set multiple bits in a register at once. In assembly,
> I'd mask off the bits I wanted to effect with an AND, then OR in my
> desired value.
>=20
> For example, if I had a register called target, and I wanted to modify
> bits 2 and 3, I'd first AND target with b'11110011', then take the
> data I wanted to put in there (in this case b'11'), and OR target with
> b'00001100'.
>=20
> Can I combine these commands in C? Or is there a better way? I think I co=
uld do:
>=20
> target |=3D 0b11110011;
> target &=3D 0b00001100;
>=20
> But what about:
>=20
> target =3D (target | 0b11110011) & 0b00001100;

Yes, you are almost perfectly on "target" (excuse the pun) and this is inde=
ed the=20
way it's done in C. Small thing though, you say you would do the AND'ing fi=
rst and=20
then OR it, which is correct, but your example shows doing it in the opposi=
te order.=20
Likely what you meant was:

target &=3D 0b00001100;
target |=3D 0b11110011;

And yes you could do:

target =3D (target & 0b11110011) | 0b00001100;

Which I think could also be written:

(target & 0b11110011) |=3D 0b00001100;




--=20
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