satcat5::sam::SysTickTimer Class Reference

Detailed Description

Microchip SAM V71 implementation of the "TimeRef" API.

This class uses configures and uses the SysTick Timer on the SAMV71 to track elapsed time for SatCat. At instantiation, it uses the CPU frequency and desired tick rate to configure the interrupt. It will will increment member when the interrupt is triggered, and SatCat can poll this value to find elapsed time.

Definition at line 21 of file systick_timer.h.

#include <systick_timer.h>

Inheritance diagram for satcat5::sam::SysTickTimer:

Collaboration diagram for satcat5::sam::SysTickTimer:

Public Member Functions
	SysTickTimer (const u32 cpu_freq_hz, const u32 tick_rate_hz)
	Constructor requires the CPU frequency and timer tick-rate.
u32	raw () override
	Get raw tick-count,. More...
void	timer_callback (satcat5::poll::OnDemand *callback)
	Set callback for timer events. More...
TimeVal	now ()
	Create a TimeVal object using the tick-count from raw().
TimeVal	checkpoint_usec (unsigned usec)
	Create an oven-timer, set N microseconds from now. More...
TimeVal	checkpoint_msec (unsigned msec)
	Create an oven-timer, set N milliseconds from now. More...
void	busywait_usec (unsigned usec)
	If timer resolution allows, busywait for X microseconds. More...
u32	ticks_per_sec () const
	Stable accessors for unit conversion. More...
u32	ticks_per_msec () const
	Stable accessors for unit conversion. More...
u32	ticks_per_usec () const
	Stable accessors for unit conversion. More...

Public Attributes
const char *const	m_label
	Human-readable label, for debugging.
const int	m_irq_idx
	IRQ index for this interrupt handler.

Protected Member Functions
void	irq_event () override
	Method called whenever an interrupt is triggered.

Protected Attributes
u32 *	m_ctrl
unsigned int	m_tick_num = 0
satcat5::poll::OnDemand *	m_callback
u32	m_max_irqtime
	Statistics tracking for time consumed by this interrupt.

Private Attributes
u64 const	m_msec_per_tick
u64 const	m_usec_per_tick
u64 const	m_tick_per_msec
u64 const	m_tick_per_usec
satcat5::irq::Handler *	m_next

Member Function Documentation

busywait_usec()

void TimeRef::busywait_usec ( unsigned  usec )

inherited

If timer resolution allows, busywait for X microseconds.

(May return immediately if backing reference is too coarse.)

Definition at line 93 of file timeref.cc.

checkpoint_msec()

TimeVal TimeRef::checkpoint_msec ( unsigned  msec )

inherited

Create an oven-timer, set N milliseconds from now.

An over-timer TimeVal is a timestamp a short time in the future. To use it, create the TimeVal and then poll checkpoint_elapsed(). (The returned TimeVal is intended to be used exactly once.)

Definition at line 73 of file timeref.cc.

checkpoint_usec()

TimeVal TimeRef::checkpoint_usec ( unsigned  usec )

inherited

Create an oven-timer, set N microseconds from now.

An over-timer TimeVal is a timestamp a short time in the future. To use it, create the TimeVal and then poll checkpoint_elapsed(). (The returned TimeVal is intended to be used exactly once.)

Definition at line 69 of file timeref.cc.

raw()

u32 SysTickTimer::raw ( )

overridevirtual

Get raw tick-count,.

See also

TimeRef.

Implements satcat5::util::TimeRef.

Definition at line 54 of file systick_timer.cc.

ticks_per_msec()

u32 satcat5::util::TimeRef::ticks_per_msec ( ) const

inlineinherited

Stable accessors for unit conversion.

If the tick rate is low, these may return zero.

Definition at line 179 of file timeref.h.

ticks_per_sec()

u32 satcat5::util::TimeRef::ticks_per_sec ( ) const

inlineinherited

Stable accessors for unit conversion.

If the tick rate is low, these may return zero.

Definition at line 177 of file timeref.h.

ticks_per_usec()

u32 satcat5::util::TimeRef::ticks_per_usec ( ) const

inlineinherited

Stable accessors for unit conversion.

If the tick rate is low, these may return zero.

Definition at line 181 of file timeref.h.

timer_callback()

void SysTickTimer::timer_callback

(

satcat5::poll::OnDemand *

callback

)

Set callback for timer events.

(This is usually poll::timekeeper.)

Definition at line 59 of file systick_timer.cc.

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

• systick_timer.h
• systick_timer.cc