Wrapper around the nRF5 TIMER peripheral. More...

#include <nrfcxx/periph.hpp>

Data Structures
class	timestamp_type
	Class supporting (high-resolution) timing. More...

Public Member Functions
int	configure (unsigned int freq_Hz, unsigned int bitmode=TIMER_BITMODE_BITMODE_16Bit, bool use_constlat=true)
	Configure the TIMER to run as a timer. More...

void	deconfigure ()
	Deconfigure the TIMER.

unsigned int	frequency_Hz () const
	Get the configured clock frequency in Hz.

void	start ()
	Invoke TASKS_START.

void	clear ()
	Invoke TASKS_CLEAR.

void	stop ()
	Invoke TASKS_STOP.

void	shutdown ()
	Invoke TASKS_SHUTDOWN.

void	capture (unsigned int ccidx) const
	Capture the current counter using CC `ccidx`. More...

unsigned int	captured (unsigned int ccidx) const
	Return the captured counter in CC `ccidx`.

unsigned int	counter (unsigned int ccidx=0) const
	Read the current timer value. More...

unsigned int	delta (unsigned int a, unsigned int b) const
	Calculate the count distance from `a` to `b`. More...

timestamp_type	timestamp (unsigned int ccidx=0) const
	Create a timestamp instance using this timer. More...

const nrf5::TIMER_Type &	peripheral () const
	Reference the nRF5 TIMER peripheral instance used by the abstraction.

const unsigned int	ccr_count () const
	The number of capture/compare registers on the device.

Static Public Member Functions
constexpr static bool	bitmode_supported (const nrf5::TIMER_Type &timer, unsigned int bitmode)
	Verify a specific timer can support the requested bitmode. More...

static TIMER &	instance (int idx)
	Reference the abstraction instance for a specific peripheral instance. More...

Static Public Attributes
constexpr static unsigned int	cc_mask = 7
	Mask to create a valid CC index from a non-negative integer. More...

Protected Member Functions
constexpr	TIMER (const nrf5::TIMER_Type &timer)

void	capture_ (unsigned int ccidx) const
	Capture the current counter into CC `ccidx` (unvalidated).

unsigned int	captured_ (unsigned int ccidx) const
	Return the captured value in CC `ccidx` (unvalidated).

unsigned int	counter_ (unsigned int ccidx) const
	Capture and return the current counter using `ccidx` (unvalidated).

Detailed Description

Wrapper around the nRF5 TIMER peripheral.

This abstraction supports using specific timers in timer mode. Timer IRQ handler definitions and interrupt configuration, if necessary, are the responsibility of the application, as is allocation of capture/compare registers to specific roles.

Note: When a soft device is used TIMER0 is restricted to the soft device. Other TIMER instances are available to applications.

Member Function Documentation

◆ bitmode_supported()

constexpr static bool nrfcxx::periph::TIMER::bitmode_supported	(	const nrf5::TIMER_Type &	timer,
		unsigned int	bitmode
	)

inlinestaticconstexpr

Verify a specific timer can support the requested bitmode.

Note: The user is responsible for ensuring that timer references an existing nRF5x TIMER peripheral and that bitmode is a valid setting for the timer BITMODE register.

◆ capture()

void nrfcxx::periph::TIMER::capture ( unsigned int ccidx ) const

inline

Capture the current counter using CC ccidx.

Note: This function intentionally does not return the captured value, as reading it from the peripheral takes a couple clock cycles which can negatively impact instrumentation accuracy. If the overhead impact on subsequent operations is not a concern, use counter() to capture and return the current timer value.

◆ configure()

int nrfcxx::periph::TIMER::configure	(	unsigned int	freq_Hz,
		unsigned int	bitmode = `TIMER_BITMODE_BITMODE_16Bit`,
		bool	use_constlat = `true`
	)

Configure the TIMER to run as a timer.

All interrupts are cleared and disabled, and the timer counter is cleared. Configuration is performed as specified by the parameters.

Parameters

freq_Hz	the desired frequency of the timer. The value is limited by clock::hfclk::Frequency_Hz, and the actual value is the largest power-of-2 divisor of that frequency that does not exceed `freq_Hz`. Zero may be passed to deconfigure the TIMER.
bitmode	the `NRF_TIMER_Type::BITMODE.BITMODE` setting controlling the range for timer counter values.
use_constlat	pass `true` to ensure that NRF_POWER->TASKS_CONSTLAT is in force as long as the timer is configured; pass `false` if the timer can tolerate running in NRF_POWER->TASKS_LOWPWR mode. If `freq_Hz` is zero any previously-specified constant latency dependency is removed.

Returns: 0 if configuration is successful, or -1 if a parameter is invalid.

Note: The timer must be started before it is useful. Startup time may be reduced if use_constlat is true.

◆ counter()

unsigned int nrfcxx::periph::TIMER::counter ( unsigned int ccidx = 0 ) const

inline

Read the current timer value.

Since the timer counter is not exposed a capture/compare index must be provided. The caller is responsible for ensuring that ccidx is not used for other purposes that would be disrupted by invocations of counter().

Returns: the full-precision counter value.

◆ delta()

unsigned int nrfcxx::periph::TIMER::delta	(	unsigned int	a,
		unsigned int	b
	)		const

inline

Calculate the count distance from a to b.

The value is truncated based on the bitmode passed to configure().

◆ instance()

static TIMER& nrfcxx::periph::TIMER::instance ( int idx )

static

Reference the abstraction instance for a specific peripheral instance.

Parameters

idx	the peripheral instance desired.

Warning: If idx specifies a peripheral instance that does not exist on the device the system will reset into failsafe mode.

◆ timestamp()

timestamp_type nrfcxx::periph::TIMER::timestamp ( unsigned int ccidx = 0 ) const

inline

Create a timestamp instance using this timer.

Parameters

ccidx the capture/compare index to be used for counter captures.

Returns: a #timestamp_type object initialized to time activity relative to the current counter value.

Field Documentation

◆ cc_mask

constexpr static unsigned int nrfcxx::periph::TIMER::cc_mask = 7

staticconstexpr

Mask to create a valid CC index from a non-negative integer.

This allows up to 8 capture/compare registers. Not all registers are available on all timers.

The documentation for this class was generated from the following file:

nrfcxx/periph.hpp

Data Structures

Public Member Functions

Static Public Member Functions

Static Public Attributes

Protected Member Functions

Detailed Description

Member Function Documentation

◆ bitmode_supported()

◆ capture()

◆ configure()

◆ counter()

◆ delta()

◆ instance()

◆ timestamp()

Field Documentation

◆ cc_mask