Timekeeping, delays and timeouts.
Timekeeping is done with elapsed time since system boot. Time is represented in ticks, where the tick rate is defined by the current driver, usually to match the tick rate of the hardware.
Tick counts are 64 bits. At the highest supported tick rate of 1Mhz this supports representing time spans of up to ~584558 years, which is big enough for all practical purposes and allows not having to worry about overflows.
Instant represents a given instant of time (relative to system boot), and
represents the duration of a span of time. They implement the math operations you’d expect,
like addition and substraction.
An implementation of the
embedded-hal delay traits is provided by
Delay, for compatibility
with libraries from the ecosystem.
time module deals exclusively with a monotonically increasing tick count.
Therefore it has no direct support for wall-clock time (“real life” datetimes
If persistence across reboots is not needed, support can be built on top of
embassy_time by storing the offset between “seconds elapsed since boot”
and “seconds since unix epoch”.
time module is backed by a global “time driver” specified at build time.
Only one driver can be active in a program.
All methods and structs transparently call into the active driver. This makes it
possible for libraries to use
embassy_time in a driver-agnostic way without
requiring generic parameters.
For more details, check the