-----Original Message-----
>From: Josh Koffman <joshybear@gmail.com>
>Sent: Mar 12, 2015 2:56 PM
>To: "Microcontroller discussion list - Public." <piclist@mit.edu>
>Subject: Re: [PIC] Setting Multiple Bits in C
>
>On Thu, Mar 12, 2015 at 3:17 PM, Charles Craft <chucksea@mindspring.com> w=
rote:
>> If you have the space, why not put all eight bits in the table?
>
>There are actually only 2 bits that I'm worried about. In this
>particular case, they are the two LSB of the PWM value for the CCP/PWM
>peripheral. The MSB 8 bits are easy to load as they are a full byte,
>the LSB go in a control register that has other functions. So I can't
>just overwrite that and expect everything to work.
>
>> Would if be easier to read if you combine your mask and value into one v=
ariable
>> then AND that with "target"?
>
>That wold be cool, but because the starting state of the target
>register isn't guaranteed, won't I still end up in a situation where I
>need to mask and combine?
>
>> or define "target" with bit fields and set the field equal to value?
>>    http://en.wikipedia.org/wiki/Bit_field
>
>This could be interesting. I hadn't thought about defining a multi-bit
>field and just writing to it. If I did the definitions correctly,
>would:
>
>TARGETbits.PWMLSB =3D arrayofvalues[index];
>
>work, or would I still need to shift to align the array value with the
>bits I'm actually loading? My guess is that I shouldn't have to shift,
>but I am unsure.

I need to rethink through the first two items.
w.r.t. bit fields, K&R says:
   "Almost everything about fields is implementation-dependent."
You'll need to code up a sample and see what the compiler generates under t=
he covers.


>
>Thanks!
>
>Josh
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