#bit #bitfield #no-std

no-std mju-bits

no_std typed bitfield access for u8, u16, u32 and u64

3 releases (breaking)

0.3.0 Jan 3, 2020
0.2.0 Jan 2, 2020
0.1.0 Jan 2, 2020

#358 in Embedded development

Apache-2.0

17KB
281 lines

mju-bits

#[no_std] implementation of typed bitfield access for u8, u16, u32, u64 and usize.

Usage

use mju_bits::*;

struct RegisterMarker;
type Register = Storage<RegisterMarker, u32>;
type RegisterAll = BitField<Register, U0, U31>;
type RegisterFieldA = BitField<Register, U0, U7>;
type RegisterFieldB = BitField<Register, U8, U24>;

let mut reg = Register::new();
reg.set::<RegisterFieldA>(0x56);
reg.set::<RegisterFieldB>(0x1234);
assert_eq!(reg.get::<RegisterAll>(), 0x00123456);

The Storage type ensures that a field may only be used with its corresponding storage.

For example, this won't compile:

use mju_bits::*;

struct FooMarker;
type Foo = Storage<FooMarker, u8>;
type FooField = BitField<Foo, U0, U1>;

struct BarMarker;
type Bar = Storage<BarMarker, u8>;

let bar = Bar::new();

// Compiler error: FooField can not be used with Bar storage.
bar.get::<FooField>();

Roadmap

  • BitFields spanning multiple primitive types
  • Iterable sequences of BitFields, supporting functional protocol definition
  • Implementation compatible with generic consts on nightly
  • Improve types so larger bitfields can be supported - 128-bit fields break typenum
  • Others?

Changelog

  • 0.3.0 - Removal of B0..B63 aliases to avoid confusion with typenum::B0 and typenum::B1
  • 0.2.0 - Documentation and cleanup
  • 0.1.0 - Initial release

Dependencies

~155KB