sample_clock.hpp File Reference

Audio-clock frame counter — the elapsed-samples source for control code. More...

Detailed Description

Audio-clock frame counter — the elapsed-samples source for control code.

Counts stereo frames the audio driver has handed to the codec since boot. The count advances only with the audio clock, so control code that needs elapsed time (the FDP-073 scheduler's tick(elapsed_samples)) reads it instead of assuming a timer rate: the 1 kHz control timer is not sample-locked to the codec.

One writer: the audio driver calls advance() once per block, after the application callback returns. Any context may call now(). Consumers take unsigned deltas, which stay correct across the wrap every 2^32 frames (~24.8 h at 48 kHz).

The counter is a relaxed atomic: race-free between the audio thread and the control thread on the workbench, plain LDR/STR on Cortex-M7. It publishes no other data, so no ordering is needed.

Definition in file sample_clock.hpp.

#include <atomic>
#include <cstdint>

Go to the source code of this file.

Classes
class	sbl::hal::audio::SampleClock

Namespaces
namespace	sbl
	Root namespace for all Sound Byte Libs code.
namespace	sbl::hal
	Hardware abstraction: handles and convenience layers over the drivers.
namespace	sbl::hal::audio
	Audio streams and the sample clock.