HfTime.h File Reference

MCU-agnostic high-resolution monotonic time source. More...

#include <cstdint>
#include "McuSelect.h"

Include dependency graph for HfTime.h:

Go to the source code of this file.

Namespaces
namespace	hf_time

Functions
std::uint64_t	hf_time::MonotonicMs () noexcept
	Convenience milliseconds view of the monotonic counter.
std::uint64_t	hf_time::ElapsedUs (std::uint64_t t0) noexcept
	Convenience: elapsed-since-t0 in microseconds.

Detailed Description

MCU-agnostic high-resolution monotonic time source.

Public surface for higher layers (HAL handlers, middleware, application self-tests) that need a sub-millisecond timebase. The concrete implementation lives under mcu/<vendor>/<X>Time.h and is selected at compile time from McuSelect.h. Adding a new MCU is a one-folder change:

1. drop in mcu/<vendor>/<X>Time.h exposing namespace hf_time::<vendor> { void InitMonotonic(); uint64_t MonotonicUs(); },
2. extend McuSelect.h if it doesn't already detect that target,
3. add one #elif block here aliasing the new namespace into hf_time.

Why this is a static-policy header and not a virtual BaseTime:

• MonotonicUs() is a single hardware-counter read used inside tight sample loops; a vtable load + indirect call would measurably degrade self-test sampling at 50 Hz × N channels.
• There is no per-instance state to vary — the underlying counter is a process-wide resource. Virtual dispatch buys nothing.
• Header-only inlining keeps the call site to a single call instruction.

Use virtual Base* bases (BaseUart, BaseSpi, …) when the primitive owns state and dispatch happens once per logical operation; use static policy headers like this one for stateless hot-path primitives.