Detailed Description

ConfigBus Timer driver.

Device driver for the timer system defined in "cfgbus_timer.vhd". The primary purpose of this device is to act as a cycle-counting TimeRef (typically operating at 10 to 100 MHz), and an interrupt source at a programmable interval (typically at 1 kHz). In some designs, it may also act as a watchdog timer that resets the system if it has not been updated after some interval.

Definition at line 22 of file cfgbus_timer.h.

#include <cfgbus_timer.h>

Inheritance diagram for satcat5::cfg::Timer:

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Collaboration diagram for satcat5::cfg::Timer:

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Public Member Functions
	Timer (satcat5::cfg::ConfigBus *cfg, unsigned devaddr)
	Auto-configuration constructor. More...

	Timer (satcat5::cfg::ConfigBus *cfg, unsigned devaddr, u32 refclk_hz)
	Manual-configuration constructor. More...

u32	raw () override
	Read the current time. More...

satcat5::util::TimeVal	last_event ()
	Read timestamp of the last external event signal. More...

void	timer_interval (unsigned usec)
	Change the timer-interrupt interval. More...

void	timer_callback (satcat5::poll::OnDemand *callback)
	Set the callback for timer-interrupt notifications. More...

void	wdog_disable ()
	Disable the hardware watchdog function. More...

void	wdog_update (u32 usec)
	Resume or reset the watchdog countdown. 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...

Protected Member Functions
void	irq_event () override
	Interrupt service routine. More...

void	irq_check ()
	Check if this interrupt may need service. More...

void	irq_enable ()
	Enable this interrupt. More...

void	irq_disable ()
	Temporarily disable this interrupt. More...

Static Protected Member Functions
static u32	hw_ticks_per_sec (satcat5::cfg::ConfigBus *cfg, unsigned devaddr)

Protected Attributes
satcat5::cfg::Register	m_ctrl

satcat5::poll::OnDemand *	m_callback

Static Protected Attributes
static constexpr u32	WDOG_PAUSE = (u32)(-1)

static constexpr unsigned	REGADDR_WDOG = 0

static constexpr unsigned	REGADDR_CPU_HZ = 1

static constexpr unsigned	REGADDR_PERF_CTR = 2

static constexpr unsigned	REGADDR_LAST_EVT = 3

static constexpr unsigned	REGADDR_TIMER_LEN = 4

static constexpr unsigned	REGADDR_TIMER_IRQ = 5

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::cfg::ConfigBus *const	m_cfg

satcat5::cfg::Interrupt *	m_next

Constructor & Destructor Documentation

◆ Timer() [1/2]

satcat5::cfg::Timer::Timer	(	satcat5::cfg::ConfigBus *	cfg,
		unsigned	devaddr
	)

inline

Auto-configuration constructor.

This constructor reads frequency parameters at runtime.

Definition at line 29 of file cfgbus_timer.h.

◆ Timer() [2/2]

satcat5::cfg::Timer::Timer	(	satcat5::cfg::ConfigBus *	cfg,
		unsigned	devaddr,
		u32	refclk_hz
	)

inline

Manual-configuration constructor.

If the timer's clock frequency is known at build time, this alternate constructor can avoid runtime division calls.

Definition at line 35 of file cfgbus_timer.h.

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.

◆ irq_check()

void Interrupt::irq_check ( )

inherited

Check if this interrupt may need service.

If the interrupt needs service, this calls irq_event.

Definition at line 46 of file cfgbus_interrupt.cc.

◆ irq_disable()

void Interrupt::irq_disable ( )

inherited

Temporarily disable this interrupt.

Interrupts are enabled by default, but some peripherals may wish to temporary toggle this setting. For use with standard "cfgbus_interrupt" only.

Definition at line 63 of file cfgbus_interrupt.cc.

◆ irq_enable()

void Interrupt::irq_enable ( )

inherited

Enable this interrupt.

Interrupts are enabled by default, but some peripherals may wish to temporary toggle this setting. For use with standard "cfgbus_interrupt" only.

Definition at line 58 of file cfgbus_interrupt.cc.

◆ irq_event()

void Timer::irq_event ( )

overrideprotectedvirtual

Interrupt service routine.

(Child class must override this method.)

Implements satcat5::cfg::Interrupt.

Definition at line 36 of file cfgbus_timer.cc.

◆ last_event()

TimeVal Timer::last_event ( )

Read timestamp of the last external event signal.

If enabled at build time, the Timer can note the timestamp of the most recent rising edge of a discrete "event" signal. For a more precise equivalent, see satcat5::ptp::PpsInput.

Definition at line 16 of file cfgbus_timer.cc.

◆ raw()

u32 Timer::raw ( )

overridevirtual

Read the current time.

This method is required for the TimeRef API.

Returns: Clock-cycle counter, modulo 2^32.

Implements satcat5::util::TimeRef.

Definition at line 12 of file cfgbus_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 Timer::timer_callback ( satcat5::poll::OnDemand * callback )

Set the callback for timer-interrupt notifications.

In most designs, this should be linked to satcat5::poll::timekeeper.

Definition at line 24 of file cfgbus_timer.cc.

◆ timer_interval()

void Timer::timer_interval ( unsigned usec )

Change the timer-interrupt interval.

On startup/reset, the default interval is 1 millisecond. This method sets a new interval, measured in microseconds.

Definition at line 20 of file cfgbus_timer.cc.

◆ wdog_disable()

void Timer::wdog_disable ( )

Disable the hardware watchdog function.

A disabled watchdog returns to its default idle state, which stops the countdown and never requests a hardware reset. To start or resume the countdown, call wdog_update.

Definition at line 28 of file cfgbus_timer.cc.

◆ wdog_update()

void Timer::wdog_update ( u32 usec )

Resume or reset the watchdog countdown.

Enables the watchdog function and set the countdown timer to the designated interval, in microseconds. Within that interval, the user should call wdog_update again to prevent a reset request, or call wdog_disable to stop the countdown.

Definition at line 32 of file cfgbus_timer.cc.

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

Detailed Description

Public Member Functions

Protected Member Functions

Static Protected Member Functions

Protected Attributes

Static Protected Attributes

Private Attributes

Constructor & Destructor Documentation

◆ Timer() [1/2]

◆ Timer() [2/2]

Member Function Documentation

◆ busywait_usec()

◆ checkpoint_msec()

◆ checkpoint_usec()

◆ irq_check()

◆ irq_disable()

◆ irq_enable()

◆ irq_event()

◆ last_event()

◆ raw()

◆ ticks_per_msec()

◆ ticks_per_sec()

◆ ticks_per_usec()

◆ timer_callback()

◆ timer_interval()

◆ wdog_disable()

◆ wdog_update()