Trait kernel::hil::time::Ticks

pub trait Ticks: Clone + Copy + From<u32> + Debug + Ord + PartialOrd + Eq {
    // Required methods
    fn width() -> u32;
    fn into_usize(self) -> usize;
    fn into_u32(self) -> u32;
    fn wrapping_add(self, other: Self) -> Self;
    fn wrapping_sub(self, other: Self) -> Self;
    fn within_range(self, start: Self, end: Self) -> bool;
    fn max_value() -> Self;
    fn half_max_value() -> Self;
    fn from_or_max(val: u64) -> Self;
    fn saturating_scale(self, numerator: u32, denominator: u32) -> u32;

    // Provided methods
    fn usize_padding() -> u32 { ... }
    fn into_usize_left_justified(self) -> usize { ... }
    fn usize_left_justified_scale_freq<F: Frequency>() -> u32 { ... }
    fn u32_padding() -> u32 { ... }
    fn into_u32_left_justified(self) -> u32 { ... }
    fn u32_left_justified_scale_freq<F: Frequency>() -> u32 { ... }
}

An integer type defining the width of a time value, which allows clients to know when wraparound will occur.

Required Methods

fn width() -> u32

Width of the actual underlying timer in bits.

The maximum value that will be attained by this timer should be (2 ** width) - 1. In other words, the timer will wrap at exactly width bits, and then continue counting at 0.

The return value is a u32, in accordance with the bit widths specified using the BITS associated const on Rust integer types.

fn into_usize(self) -> usize

Converts the type into a usize, stripping the higher bits it if it is larger than usize and filling the higher bits with 0 if it is smaller than usize.

fn into_u32(self) -> u32

Converts the type into a u32, stripping the higher bits it if it is larger than u32 and filling the higher bits with 0 if it is smaller than u32. Included as a simple helper since Tock uses u32 pervasively and most platforms are 32 bits.

fn wrapping_add(self, other: Self) -> Self

Add two values, wrapping around on overflow using standard unsigned arithmetic.

fn wrapping_sub(self, other: Self) -> Self

Subtract two values, wrapping around on underflow using standard unsigned arithmetic.

fn within_range(self, start: Self, end: Self) -> bool

Returns whether the value is in the range of [start, end) using unsigned arithmetic and considering wraparound. It returns trueif, incrementing fromstart, the value will be reached before end. Put another way, it returns (self - start) < (end - start)` in unsigned arithmetic.

fn max_value() -> Self

Returns the maximum value of this type, which should be (2^width)-1.

fn half_max_value() -> Self

Returns the half the maximum value of this type, which should be (2^width-1).

fn from_or_max(val: u64) -> Self

Converts the specified val into this type if it fits otherwise the max_value() is returned

fn saturating_scale(self, numerator: u32, denominator: u32) -> u32

Scales the ticks by the specified numerator and denominator. If the resulting value would be greater than u32,u32::MAX is returned instead

Provided Methods

fn usize_padding() -> u32

The amount of bits required to left-justify this ticks value range (filling the lower bits with 0) for it wrap at (2 ** usize::BITS) - 1 bits. For timers with a width larger than usize, this value will be 0 (i.e., they can simply be truncated to usize::BITS bits).

fn into_usize_left_justified(self) -> usize

Converts the type into a usize, left-justified and right-padded with 0 such that it is guaranteed to wrap at (2 ** usize::BITS) - 1. If it is larger than usize::BITS bits, any higher bits are stripped.

The resulting tick rate will possibly be higher (multiplied by 2 ** usize_padding()). Use usize_left_justified_scale_freq to convert the underlying timer’s frequency into the padded ticks frequency in Hertz.

fn usize_left_justified_scale_freq<F: Frequency>() -> u32

Convert the generic Frequency argument into a frequency (Hertz) describing a left-justified ticks value as returned by Ticks::into_usize_left_justified.

fn u32_padding() -> u32

The amount of bits required to left-justify this ticks value range (filling the lower bits with 0) for it wrap at (2 ** 32) - 1 bits. For timers with a width larger than 32, this value will be 0 (i.e., they can simply be truncated to 32-bits).

The return value is a u32, in accordance with the bit widths specified using the BITS associated const on Rust integer types.

fn into_u32_left_justified(self) -> u32

Converts the type into a u32, left-justified and right-padded with 0 such that it is guaranteed to wrap at (2 ** 32) - 1. If it is larger than 32-bits, any higher bits are stripped.

The resulting tick rate will possibly be higher (multiplied by 2 ** u32_padding()). Use u32_left_justified_scale_freq to convert the underlying timer’s frequency into the padded ticks frequency in Hertz.

fn u32_left_justified_scale_freq<F: Frequency>() -> u32

Convert the generic Frequency argument into a frequency (Hertz) describing a left-justified ticks value as returned by Ticks::into_u32_left_justified.

Object Safety

This trait is not object safe.

Implementors

impl Ticks for Ticks16

impl Ticks for Ticks24

impl Ticks for Ticks32

impl Ticks for Ticks64