Clock driver

Files
file	clock.c
	Software clock implementation for the nRF52.

Functions
static void	rtc_handler (nrf_drv_rtc_int_type_t int_type)
	Function for handling the RTC0 interrupts. More...
static void	lfclk_config (void)
	Function starting the internal LFCLK XTAL oscillator.
static void	rtc_config (void)
	Function initialization and configuration of RTC driver instance.
void	clock_init (void)
	Initialize the clock library. More...
CCIF clock_time_t	clock_time (void)
	Get the current clock time. More...
CCIF unsigned long	clock_seconds (void)
	Get the current value of the platform seconds. More...
void	clock_wait (clock_time_t i)
	Wait for a given number of ticks. More...
void	clock_delay_usec (uint16_t dt)
	Delay a given number of microseconds. More...
void	clock_delay (unsigned int i)
	Obsolete delay function but we implement it here since some code still uses it. More...

Variables
const nrf_drv_rtc_t	rtc = NRF_DRV_RTC_INSTANCE(PLATFORM_RTC_INSTANCE_ID)
	RTC instance used for platform clock.

Detailed Description

Function Documentation

void clock_delay

(

unsigned int

i

)

Obsolete delay function but we implement it here since some code still uses it.

Obsolete delay function but we implement it here since some code still uses it.

Definition at line 162 of file clock.c.

References clock_delay_usec().

void clock_delay_usec

(

uint16_t

dt

)

Delay a given number of microseconds.

Parameters

dt	How many microseconds to delay.

Note

Interrupts could increase the delay by a variable amount.

Definition at line 152 of file clock.c.

void clock_init

(

void

)

Initialize the clock library.

This function initializes the clock library and should be called from the main() function of the system.

Initialize the clock library.

Initialize the clock library.

We initialise the SysTick to fire 128 interrupts per second, giving us a value of 128 for CLOCK_SECOND

We also initialise GPT0:Timer A, which is used by clock_delay_usec(). We use 16-bit range (individual), count-down, one-shot, no interrupts. The prescaler is computed according to the system clock in order to get 1 tick per usec.

Definition at line 111 of file clock.c.

References lfclk_config(), and rtc_config().

CCIF unsigned long clock_seconds

(

void

)

Get the current value of the platform seconds.

This could be the number of seconds since startup, or since a standard epoch.

Returns

The value.

Get the current value of the platform seconds.

The comparison avoids the need to disable clock interrupts for an atomic read of the four-byte variable.

Definition at line 136 of file clock.c.

CCIF clock_time_t clock_time

(

void

)

Get the current clock time.

This function returns the current system clock time.

Returns

The current clock time, measured in system ticks.

Get the current clock time.

When 16 bit it typically wraps every 10 minutes. The comparison avoids the need to disable clock interrupts for an atomic read of the multi-byte variable.

Definition at line 121 of file clock.c.

void clock_wait

(

clock_time_t

t

)

Wait for a given number of ticks.

Parameters

t	How many ticks.

Definition at line 142 of file clock.c.

References clock_time(), and start().

static void rtc_handler ( nrf_drv_rtc_int_type_t  int_type )

static

Function for handling the RTC0 interrupts.

Parameters

int_type

Type of interrupt to be handled

Definition at line 71 of file clock.c.

Referenced by rtc_config().