High Resolution Timers

Macros
#define	CPUTIME_LT(__t1, __t2)   ((int32_t) ((__t1) - (__t2)) < 0)
#define	CPUTIME_GT(__t1, __t2)   ((int32_t) ((__t1) - (__t2)) > 0)
#define	CPUTIME_GEQ(__t1, __t2)   ((int32_t) ((__t1) - (__t2)) >= 0)
#define	CPUTIME_LEQ(__t1, __t2)   ((int32_t) ((__t1) - (__t2)) <= 0)

Functions
int	os_cputime_init (uint32_t clock_freq)
uint32_t	os_cputime_get32 (void)
uint32_t	os_cputime_nsecs_to_ticks (uint32_t nsecs)
uint32_t	os_cputime_ticks_to_nsecs (uint32_t ticks)
void	os_cputime_delay_nsecs (uint32_t nsecs)
uint32_t	os_cputime_usecs_to_ticks (uint32_t usecs)
uint32_t	os_cputime_ticks_to_usecs (uint32_t ticks)
void	os_cputime_delay_ticks (uint32_t ticks)
void	os_cputime_delay_usecs (uint32_t usecs)
void	os_cputime_timer_init (struct hal_timer *timer, hal_timer_cb fp, void *arg)
int	os_cputime_timer_start (struct hal_timer *timer, uint32_t cputime)
int	os_cputime_timer_relative (struct hal_timer *timer, uint32_t usecs)
void	os_cputime_timer_stop (struct hal_timer *timer)

Detailed Description

Macro Definition Documentation

CPUTIME_GEQ

#define CPUTIME_GEQ	(		__t1,
			__t2
	)		((int32_t) ((__t1) - (__t2)) >= 0)

evaluates to true if t1 is on or after t2 in time

CPUTIME_GT

#define CPUTIME_GT	(		__t1,
			__t2
	)		((int32_t) ((__t1) - (__t2)) > 0)

evaluates to true if t1 is after t2 in time

CPUTIME_LEQ

#define CPUTIME_LEQ	(		__t1,
			__t2
	)		((int32_t) ((__t1) - (__t2)) <= 0)

evaluates to true if t1 is on or before t2 in time

CPUTIME_LT

#define CPUTIME_LT	(		__t1,
			__t2
	)		((int32_t) ((__t1) - (__t2)) < 0)

evaluates to true if t1 is before t2 in time

Function Documentation

os_cputime_delay_nsecs()

void os_cputime_delay_nsecs

(

uint32_t

nsecs

)

Wait until 'nsecs' nanoseconds has elapsed. This is a blocking delay. Not defined if OS_CPUTIME_FREQ_PWR2 is defined.

Parameters

nsecs

The number of nanoseconds to wait.

os_cputime_delay_ticks()

void os_cputime_delay_ticks

(

uint32_t

ticks

)

Wait until the number of ticks has elapsed. This is a blocking delay.

Parameters

ticks

The number of ticks to wait.

os_cputime_delay_usecs()

void os_cputime_delay_usecs

(

uint32_t

usecs

)

Wait until 'usecs' microseconds has elapsed. This is a blocking delay.

Parameters

usecs

The number of usecs to wait.

os_cputime_get32()

uint32_t os_cputime_get32

(

void

)

Returns the low 32 bits of cputime.

Returns

uint32_t The lower 32 bits of cputime

os_cputime_init()

int os_cputime_init

(

uint32_t

clock_freq

)

Initialize the cputime module. This must be called after os_init is called and before any other timer API are used. This should be called only once and should be called before the hardware timer is used.

Parameters

clock_freq

The desired cputime frequency, in hertz (Hz).

Returns

int 0 on success; -1 on error.

os_cputime_nsecs_to_ticks()

uint32_t os_cputime_nsecs_to_ticks

(

uint32_t

nsecs

)

Converts the given number of nanoseconds into cputime ticks. Not defined if OS_CPUTIME_FREQ_PWR2 is defined.

Parameters

usecs

The number of nanoseconds to convert to ticks

Returns

uint32_t The number of ticks corresponding to 'nsecs'

os_cputime_ticks_to_nsecs()

uint32_t os_cputime_ticks_to_nsecs

(

uint32_t

ticks

)

Convert the given number of ticks into nanoseconds. Not defined if OS_CPUTIME_FREQ_PWR2 is defined.

Parameters

ticks

The number of ticks to convert to nanoseconds.

Returns

uint32_t The number of nanoseconds corresponding to 'ticks'

os_cputime_ticks_to_usecs()

uint32_t os_cputime_ticks_to_usecs

(

uint32_t

ticks

)

Convert the given number of ticks into microseconds.

Parameters

ticks

The number of ticks to convert to microseconds.

Returns

uint32_t The number of microseconds corresponding to 'ticks'

os_cputime_timer_init()

void os_cputime_timer_init	(	struct hal_timer *	timer,
		hal_timer_cb	fp,
		void *	arg
	)

Initialize a CPU timer, using the given HAL timer.

Parameters

timer	The timer to initialize. Cannot be NULL.
fp	The timer callback function. Cannot be NULL.
arg	Pointer to data object to pass to timer.

os_cputime_timer_relative()

int os_cputime_timer_relative	(	struct hal_timer *	timer,
		uint32_t	usecs
	)

Sets a cpu timer that will expire 'usecs' microseconds from the current cputime.

NOTE: This must be called when the timer is stopped.

Parameters

timer	Pointer to timer. Cannot be NULL.
usecs	The number of usecs from now at which the timer will expire.

Returns

int 0 on success; EINVAL if timer already started or timer struct invalid

os_cputime_timer_start()

int os_cputime_timer_start	(	struct hal_timer *	timer,
		uint32_t	cputime
	)

Start a cputimer that will expire at 'cputime'. If cputime has already passed, the timer callback will still be called (at interrupt context).

NOTE: This must be called when the timer is stopped.

Parameters

timer	Pointer to timer to start. Cannot be NULL.
cputime	The cputime at which the timer should expire.

Returns

int 0 on success; EINVAL if timer already started or timer struct invalid

os_cputime_timer_stop()

void os_cputime_timer_stop

(

struct hal_timer *

timer

)

Stops a cputimer from running. The timer is removed from the timer queue and interrupts are disabled if no timers are left on the queue. Can be called even if timer is not running.

Parameters

timer

Pointer to cputimer to stop. Cannot be NULL.

os_cputime_usecs_to_ticks()

uint32_t os_cputime_usecs_to_ticks

(

uint32_t

usecs

)

Converts the given number of microseconds into cputime ticks.

Parameters

usecs

The number of microseconds to convert to ticks

Returns

uint32_t The number of ticks corresponding to 'usecs'