ARM(R) SysTick driver

ARM(R) SysTick driver. More...

Modules
	ARM(R) SysTick driver configuration

Data Structures
struct	nrfx_systick_state_t
	The value type that holds the SysTick state. More...

Functions
void	nrfx_systick_init (void)
	Function for configuring and starting the timer. More...
void	nrfx_systick_get (nrfx_systick_state_t *p_state)
	Function for getting the current SysTick state. More...
bool	nrfx_systick_test (nrfx_systick_state_t const *p_state, uint32_t us)
	Function for testing if the current time is higher in relation to the remembered state. More...
void	nrfx_systick_delay_ticks (uint32_t ticks)
	Function for delaying the execution for the specified amount of CPU ticks. More...
void	nrfx_systick_delay_us (uint32_t us)
	Function for delaying the execution for the specified amount of microseconds. More...
void	nrfx_systick_delay_ms (uint32_t ms)
	Function for delaying the execution for the specified amount of milliseconds. More...

Detailed Description

ARM(R) SysTick driver.

This driver configures ARM(R) SysTick as a free-running timer. This timer is used to generate delays and pool for timeouts. Only relatively short timeouts are supported. The SysTick works on 64MHz and is 24-bit wide. This means that it overflows around 4 times per second and around 250 microseconds will be the highest supported time in the library. As it is hard to detect if the overflow is generated without using interrupts, the maximum delay range is halved for safety reasons.

Function Documentation

void nrfx_systick_delay_ms

(

uint32_t

ms

)

Function for delaying the execution for the specified amount of milliseconds.

This delay function removes the limits of the highest possible delay value.

Parameters

[in]

ms

Number of milliseconds when the execution is blocked.

void nrfx_systick_delay_ticks

(

uint32_t

ticks

)

Function for delaying the execution for the specified amount of CPU ticks.

Parameters

[in]

ticks

Number of CPU ticks when the execution is blocked.

void nrfx_systick_delay_us

(

uint32_t

us

)

Function for delaying the execution for the specified amount of microseconds.

Parameters

[in]

us

Number of microseconds when the execution is blocked.

void nrfx_systick_get

(

nrfx_systick_state_t *

p_state

)

Function for getting the current SysTick state.

Function gets the current state of the SysTick timer. It can be used to check time-out by nrfx_systick_test.

Parameters

[out]

p_state

The pointer to the state variable to be filled.

void nrfx_systick_init

(

void

)

Function for configuring and starting the timer.

Function configures SysTick as a free-running timer without interrupt.

bool nrfx_systick_test	(	nrfx_systick_state_t const *	p_state,
		uint32_t	us
	)

Function for testing if the current time is higher in relation to the remembered state.

Parameters

[in]	p_state	Remembered state set by nrfx_systick_get
[in]	us	Required time-out.

Return values

true	The current time is higher than the specified state plus the given time-out.
false	The current time is lower than the specified state plus the given time-out.