ztimer frequency conversion modules

ztimer frequency conversion modules More...

Detailed Description

ztimer frequency conversion modules

ztimer provides multiple conversion modules:

• ztimer_convert_shift: should be used if the fraction is a power of two.
• ztimer_convert_frac: should be used if the fraction is not a power of two. rounding might be a bit off for some fractions.
• ztimer_convert_muldiv64: can be used instead of ztimer_convert_frac, if 64bit division is cheap on the target board.

Topics
	conversion using shifts
	Translates between clock tick rates
	plain 64bit carithmetic
	ztimer frequency conversion module (64bit arithmetic)
	ztimer_convert_frac frequency conversion layer
	Translates between clock tick rates

Files
file	convert.h
	ztimer frequency conversion base module

Data Structures
struct	ztimer_convert_t
	base type for ztimer convert modules More...

Functions
void	ztimer_convert_init (ztimer_convert_t *ztimer_convert, ztimer_clock_t *lower, uint32_t max_value)
	Initialization function for ztimer_convert_t.
void	ztimer_convert_cancel (ztimer_clock_t *clock)
	ztimer_convert common cancel() op
void	ztimer_convert_start (ztimer_clock_t *clock)
	ztimer_convert common start() op
void	ztimer_convert_stop (ztimer_clock_t *clock)
	ztimer_convert common stop() op

Function Documentation

ztimer_convert_cancel()

void ztimer_convert_cancel

(

ztimer_clock_t *

clock

)

ztimer_convert common cancel() op

Used by some conversion modules as ztimer_clock_t::ops.cancel().

Parameters

[in]

clock

ztimer clock to operate on

ztimer_convert_init()

void ztimer_convert_init	(	ztimer_convert_t *	ztimer_convert,
		ztimer_clock_t *	lower,
		uint32_t	max_value )

Initialization function for ztimer_convert_t.

max_value needs to be set to the maximum value that can be converted without overflowing. E.g., if the conversion module slows down a lower clock by factor X, max_value needs to be set to UINT32_MAX / X.

Parameters

[in,out]	ztimer_convert	object to initialize
[in]	lower	lower ztimer clock
[in]	max_value	maximum value for this clock's set()

ztimer_convert_start()

void ztimer_convert_start

(

ztimer_clock_t *

clock

)

ztimer_convert common start() op

Used by some conversion modules as ztimer_clock_t::ops.start().

Parameters

[in]

clock

ztimer clock to operate on

ztimer_convert_stop()

void ztimer_convert_stop

(

ztimer_clock_t *

clock

)

ztimer_convert common stop() op

Used by some conversion modules as ztimer_clock_t::ops.stop().

Parameters

[in]

clock

ztimer clock to operate on