gnupic: Bit variables in C
Subject:
Re: Bit variables in C
From:
Mike ####@####.####
Date:
15 Nov 2000 04:28:27 -0000
Message-Id: <20001114232957.A21767@earthlink.net>
Scott Dattalo wrote:
>
> It's not part of ANSI, but SDCC has support for a `bit' type. This makes sense
> if your target MCU is an 8051 (because of the bit instructions). However, how
> useful is it for the PIC? I'd personally stay away from it since it is not
> portable. OTOH, I'm probably going to keep it in since it's already part of
> SDCC. Any opinions?
Well, it's not quite a bit type, but according to K&R ANSI C does have
support for a bit-field type. Could this somehow be used in someway to
provide some sort of portability?
Quick synopsis:
struct {
unsigned int flag_a : 1;
unsigned int flag_b : 1;
unsigned int flag_c : 1;
} flags;
This defines a variable 'flags' that contains three 1-bit fields. I don't
see why it couldn't be used for single 1-bit flags as well. Perhaps via a
typedef or a macro somehow?
Perhaps I should point out that I am very much still a beginner at coding,
and so may well be talking out my arse here. So if this isn't possible, I
won't be too surprised. ;)
--
Mike Werner KA8YSD | He that is slow to believe anything and
| everything is of great understanding,
'91 GS500E | for belief in one false principle is the
Morgantown WV | beginning of all unwisdom.
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