Timing Measurement APIs

Timing Measurement APIs. More...

Topics
	Arch specific Timing Measurement APIs
	Arch specific Timing Measurement APIs.
	Board specific Timing Measurement APIs
	Board specific Timing Measurement APIs.
	SoC specific Timing Measurement APIs
	SoC specific Timing Measurement APIs.

Functions
void	timing_init (void)
	Initialize the timing subsystem.
void	timing_start (void)
	Signal the start of the timing information gathering.
void	timing_stop (void)
	Signal the end of the timing information gathering.
uint64_t	timing_ns_get (void)
	Return a monotonic timestamp in nanoseconds.
static timing_t	timing_counter_get (void)
	Return timing counter.
static uint64_t	timing_cycles_get (volatile timing_t *const start, volatile timing_t *const end)
	Get number of cycles between start and end.
static uint64_t	timing_freq_get (void)
	Get frequency of counter used (in Hz).
static uint64_t	timing_cycles_to_ns (uint64_t cycles)
	Convert number of cycles into nanoseconds.
static uint64_t	timing_cycles_to_ns_avg (uint64_t cycles, uint32_t count)
	Convert number of cycles into nanoseconds with averaging.
static uint32_t	timing_freq_get_mhz (void)
	Get frequency of counter used (in MHz).

Detailed Description

Timing Measurement APIs.

The timing measurement APIs can be used to obtain execution time of a section of code to aid in analysis and optimization.

Please note that the timing functions may use a different timer than the default kernel timer, where the timer being used is specified by architecture, SoC or board configuration.

Function Documentation

timing_counter_get()

timing_t timing_counter_get ( void )

inlinestatic

#include <zephyr/timing/timing.h>

Return timing counter.

Returns

Timing counter.

timing_cycles_get()

uint64_t timing_cycles_get ( volatile timing_t *const start, volatile timing_t *const end )

inlinestatic

#include <zephyr/timing/timing.h>

Get number of cycles between start and end.

For some architectures or SoCs, the raw numbers from counter need to be scaled to obtain actual number of cycles.

Parameters

start	Pointer to counter at start of a measured execution.
end	Pointer to counter at stop of a measured execution.

Returns

Number of cycles between start and end.

timing_cycles_to_ns()

uint64_t timing_cycles_to_ns ( uint64_t cycles )

inlinestatic

#include <zephyr/timing/timing.h>

Convert number of cycles into nanoseconds.

Parameters

cycles

Number of cycles

Returns

Converted time value

timing_cycles_to_ns_avg()

uint64_t timing_cycles_to_ns_avg ( uint64_t cycles, uint32_t count )

inlinestatic

#include <zephyr/timing/timing.h>

Convert number of cycles into nanoseconds with averaging.

Parameters

cycles	Number of cycles
count	Times of accumulated cycles to average over

Returns

Converted time value

timing_freq_get()

uint64_t timing_freq_get ( void )

inlinestatic

#include <zephyr/timing/timing.h>

Get frequency of counter used (in Hz).

Returns

Frequency of counter used for timing in Hz.

timing_freq_get_mhz()

uint32_t timing_freq_get_mhz ( void )

inlinestatic

#include <zephyr/timing/timing.h>

Get frequency of counter used (in MHz).

Returns

Frequency of counter used for timing in MHz.

timing_init()

void timing_init

(

void

)

#include <zephyr/timing/timing.h>

Initialize the timing subsystem.

Perform the necessary steps to initialize the timing subsystem.

timing_ns_get()

uint64_t timing_ns_get

(

void

)

#include <zephyr/timing/timing.h>

Return a monotonic timestamp in nanoseconds.

Unlike timing_counter_get(), whose backing counter may be narrower than 64 bits and wrap, this returns a 64-bit nanosecond value that increases monotonically across counter wraps. It is intended for consumers that need an absolute time reference (e.g. trace event timestamps) rather than the duration between two explicit readings.

The value is always monotonic. It is also accurate as long as the function is called at least once per wrap period of the underlying counter; if calls are further apart the value still only increases but may undercount the true elapsed time.

Returns

Monotonic timestamp in nanoseconds.

timing_start()

void timing_start

(

void

)

#include <zephyr/timing/timing.h>

Signal the start of the timing information gathering.

Signal to the timing subsystem that timing information will be gathered from this point forward.

timing_stop()

void timing_stop

(

void

)

#include <zephyr/timing/timing.h>

Signal the end of the timing information gathering.

Signal to the timing subsystem that timing information is no longer being gathered from this point forward.