diff options
Diffstat (limited to 'embassy-time/src/lib.rs')
| -rw-r--r-- | embassy-time/src/lib.rs | 43 |
1 files changed, 1 insertions, 42 deletions
diff --git a/embassy-time/src/lib.rs b/embassy-time/src/lib.rs index a6454d55e..a6c5d78cc 100644 --- a/embassy-time/src/lib.rs +++ b/embassy-time/src/lib.rs | |||
| @@ -1,50 +1,9 @@ | |||
| 1 | #![cfg_attr(not(any(feature = "std", feature = "wasm")), no_std)] | 1 | #![cfg_attr(not(any(feature = "std", feature = "wasm")), no_std)] |
| 2 | #![cfg_attr(feature = "nightly", feature(generic_associated_types, type_alias_impl_trait))] | 2 | #![cfg_attr(feature = "nightly", feature(generic_associated_types, type_alias_impl_trait))] |
| 3 | #![doc = include_str!("../README.md")] | ||
| 3 | #![allow(clippy::new_without_default)] | 4 | #![allow(clippy::new_without_default)] |
| 4 | #![warn(missing_docs)] | 5 | #![warn(missing_docs)] |
| 5 | 6 | ||
| 6 | //! Timekeeping, delays and timeouts. | ||
| 7 | //! | ||
| 8 | //! Timekeeping is done with elapsed time since system boot. Time is represented in | ||
| 9 | //! ticks, where the tick rate is defined by the current driver, usually to match | ||
| 10 | //! the tick rate of the hardware. | ||
| 11 | //! | ||
| 12 | //! Tick counts are 64 bits. At the highest supported tick rate of 1Mhz this supports | ||
| 13 | //! representing time spans of up to ~584558 years, which is big enough for all practical | ||
| 14 | //! purposes and allows not having to worry about overflows. | ||
| 15 | //! | ||
| 16 | //! [`Instant`] represents a given instant of time (relative to system boot), and [`Duration`] | ||
| 17 | //! represents the duration of a span of time. They implement the math operations you'd expect, | ||
| 18 | //! like addition and substraction. | ||
| 19 | //! | ||
| 20 | //! # Delays and timeouts | ||
| 21 | //! | ||
| 22 | //! [`Timer`] allows performing async delays. [`Ticker`] allows periodic delays without drifting over time. | ||
| 23 | //! | ||
| 24 | //! An implementation of the `embedded-hal` delay traits is provided by [`Delay`], for compatibility | ||
| 25 | //! with libraries from the ecosystem. | ||
| 26 | //! | ||
| 27 | //! # Wall-clock time | ||
| 28 | //! | ||
| 29 | //! The `time` module deals exclusively with a monotonically increasing tick count. | ||
| 30 | //! Therefore it has no direct support for wall-clock time ("real life" datetimes | ||
| 31 | //! like `2021-08-24 13:33:21`). | ||
| 32 | //! | ||
| 33 | //! If persistence across reboots is not needed, support can be built on top of | ||
| 34 | //! `embassy_time` by storing the offset between "seconds elapsed since boot" | ||
| 35 | //! and "seconds since unix epoch". | ||
| 36 | //! | ||
| 37 | //! # Time driver | ||
| 38 | //! | ||
| 39 | //! The `time` module is backed by a global "time driver" specified at build time. | ||
| 40 | //! Only one driver can be active in a program. | ||
| 41 | //! | ||
| 42 | //! All methods and structs transparently call into the active driver. This makes it | ||
| 43 | //! possible for libraries to use `embassy_time` in a driver-agnostic way without | ||
| 44 | //! requiring generic parameters. | ||
| 45 | //! | ||
| 46 | //! For more details, check the [`driver`] module. | ||
| 47 | |||
| 48 | // This mod MUST go first, so that the others see its macros. | 7 | // This mod MUST go first, so that the others see its macros. |
| 49 | pub(crate) mod fmt; | 8 | pub(crate) mod fmt; |
| 50 | 9 | ||