Why not just put the four values in an array and use your
data value as the index to the array?

Allen

> -----Original Message-----
> From: piclist-bounces@mit.edu [mailto:piclist-
> bounces@mit.edu] On Behalf Of Richard R. Pope
> Sent: Tuesday, September 15, 2015 12:06 AM
> To: Microcontroller discussion list - Public.
> Subject: Re: SV: [PIC]: Troubles with a 16f628a!
>=20
> Hello all,
>      Could someone please help me do this in C?
> Thanks,
> rich!
>=20
> On 9/14/2015 11:14 AM, Byron Jeff wrote:
> > Richard,
> >
> > Your description below screams table. Since it's only 2
bits,
> the table
> > would be 4 entries long:
> >
> > TableA: ; W is input. Returns table entry in W.
> > 	andlw	0x3	; make sure only 2 lowest bits are
used
> > 	addwf	PC,F	; jump to appropriate table entry
> > 	retlw	0x82	; return 1001 in bits 7-6,3-2 if
input is
> 00
> > 	retlw	0x04	; return 0010 in bits 7-6,3=3D2 if
input is
> 01
> > 	retlw	0x40	; return 0100 in bits 7-6,3=3D2 if
input is
> 10
> > 	retlw	0x80	; return 1000 in bits 7-6,3=3D2 if
input is
> 11
> >
> > Make a similar table for B.
> >
> > Then all you'd need to do is read the port, clear the
output
> bits, call the
> > table routine, OR back in the results, and write the
whole
> mess back to the
> > port.
> >
> > Hope this helps,
> >
> > BAJ
> >
> > On Mon, Sep 14, 2015 at 10:31:15AM -0500, Richard R.
Pope
> wrote:
> >> Jan-Erik,
> >>       I guess my next question is about packing the
register.
> The RA0-1
> >> and RB0-1 bits are my inputs. On Port A the output pins
are
> 2-3 and 6-7.
> >> On Port B it is 2-5. So if I have two output registers.
One
> called
> >> OutputA and the other OutputB. When the input is 0-0
then
> the output is
> >> 1-0-0-1. If the input is 0-1 then the output is
0-0-1-0. If it is
> 1-0
> >> the output is 0-1-0-0 and if it is 1-1 the the output
is 1-0-0-0.
> I
> >> guess we should define some constants called Bit# such
as
> Bit0, Bit1,
> >> Bit2 and so forth to Bit7. These should be set to 1, 2,
4, 8,
> and so
> >> forth up to 128. We first have to clear the registers
to zero
> with
> >> OutputA or B =3D 0; So do we add RA, B 0 and 1 together?
And
> here is where
> >> I get lost.  I just don't understand how to turn RA and
B 0
> and 1 in to
> >> the proper number to put into the output bits. Would
you
> please help me
> >> with this.
> >> Thanks,
> >> rich!
> >>
> >> P.S. This is how it should look.
> >> ---------------------------------
----------------------------------
> >>                   |    Input    |    Output
|
> >>             |    Input    |    Output |
> >>                   |   Bits       |    Bits    PortA
|
> >>            |    Bits      |    Bits   PortB |
> >>                   |-----|-----|-----|-----|-----|-----|
> >> |-----|-----|-----|-----|-----|------|
> >>                   |   1  |   0   |   2   |   3  |   6
|   7  |
> >>                |   1   |   0  |   2   |   3  |   4   |
5    |
> >>                   |-----|-----|-----|-----|-----|-----|
> >> |-----|-----|-----|-----|-----|------|
> >>                   |   0   |   0  |  1   |   0   |   0
|   1  |
> >>                   |   0  |    0  |   1   |   0  |    0
| 1    |
> >>                   |-----|-----|-----|-----|-----|-----|
> >> |-----|-----|-----|-----|------|-----|
> >>                   |   0   |  1   |  0   |   1   |   0
|   0 |
> >>                   |   0  |    1  |   0  |   1   |    0
|   0   |
> >>                   |-----|-----|-----|-----|-----|-----|
> >> |-----|-----|-----|-----|------|-----|
> >>                   |   1   |   0  |   0  |   0   |   1
|   0  |
> >>                |   1   |   0  |   0  |   0   |   1    |
0   |
> >>                   |-----|-----|-----|-----|-----|-----|
> >> |-----|-----|-----|-----|------|-----|
> >>                   |   1  |   1   |   0   |   0  |   0
|   1 |
> >>                   |   1  |    1  |   0   |   0  |    0
|   1   |
> >>                   |-----|-----|-----|-----|-----|-----|
> >> |-----|-----|-----|-----|------|-----|
> >> Thanks,
> >> rich!
> >>
> >>
> >> On 9/13/2015 6:00 AM, Jan-Erik S=F6derholm wrote:
> >>
> >> --
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