PIT_LifetimeTimer Class Reference

Interface for using the "Life Time TImer" functionality of the Periodic Interrut Timer on Teensy 4.x microcontrollers. The module uses Channel 0 and 1 of the 4 PIT channels. More...

#include <lifetime_timer.hpp>

Public Member Functions
	PIT_LifetimeTimer ()
void	init () __attribute__((always_inline))
	Sets up Timer 0 and Timer 1 channels for Lifetime timing - chained configuration. This function also makes a call to enable PIT timers. The timers are aet at maximum values and will start downcounting once PIT_LifetimeTimer::start() method is called. More...
void	start () __attribute__((always_inline))
	Starts the timers for down counting. More...
void	stop () __attribute__((always_inline))
	Stops the timers from counting. The timers values will freeze. More...
void	reset () __attribute__((always_inline))
	Stops the timers and resets the timer back to the init value (max) - 0xFFFFFFFFFFFFFF. More...
uint64_t	read_val () __attribute__((always_inline))
	Returns the complete 64-bit timing value. More...
uint32_t	read_low_val () __attribute__((always_inline))
	Returns the lower 32-bit half of the 64-bit timing value. More...
uint32_t	read_high_val () __attribute__((always_inline))
	Returns the higher 32-bit half of the 64-bit timing value. More...
uint64_t	elapsed64 () __attribute__((always_inline))
	Returns the elapsed duration from the start call of the timer. The return is the complete 64bit value. More...
uint32_t	elapsed32 () __attribute__((always_inline))
	Returns the elapsed duration from the start call of the timer. The return is the lower 32-bit half elapsed time value. More...

Detailed Description

Interface for using the "Life Time TImer" functionality of the Periodic Interrut Timer on Teensy 4.x microcontrollers. The module uses Channel 0 and 1 of the 4 PIT channels.

Attention

The module has no checks on the use of CH0 and CH1 by external drivers, however, the interface enforces a singleton template and can only be constructed once.

The module does not set the clock frequency and uses either the default or the one set globally (as is the only use case) by external drivers outside its scope.

Source : Code adapted from IMXRT Manual Page 2977.

Todo:

Resolve Singleton template - constexpr static issue.

Constructor & Destructor Documentation

PIT_LifetimeTimer()

PIT_LifetimeTimer::PIT_LifetimeTimer ( )

inline

Member Function Documentation

elapsed32()

uint32_t PIT_LifetimeTimer::elapsed32 ( )

inline

Returns the elapsed duration from the start call of the timer. The return is the lower 32-bit half elapsed time value.

Warning

If the elapsed duration is greater than the 32-bit rollover time, then the quantity returned is meaningless. Hence, use of this function should be reserved for measuring small time durarions.

elapsed64()

uint64_t PIT_LifetimeTimer::elapsed64 ( )

inline

Returns the elapsed duration from the start call of the timer. The return is the complete 64bit value.

init()

void PIT_LifetimeTimer::init ( )

inline

Sets up Timer 0 and Timer 1 channels for Lifetime timing - chained configuration. This function also makes a call to enable PIT timers. The timers are aet at maximum values and will start downcounting once PIT_LifetimeTimer::start() method is called.

Attention

Reference : Code adapted from IMXRT Manual Page 2977.

The timers will operate at the clock frequency set for PIT timers outside this library.

read_high_val()

uint32_t PIT_LifetimeTimer::read_high_val ( )

inline

Returns the higher 32-bit half of the 64-bit timing value.

read_low_val()

uint32_t PIT_LifetimeTimer::read_low_val ( )

inline

Returns the lower 32-bit half of the 64-bit timing value.

read_val()

uint64_t PIT_LifetimeTimer::read_val ( )

inline

Returns the complete 64-bit timing value.

reset()

void PIT_LifetimeTimer::reset ( )

inline

Stops the timers and resets the timer back to the init value (max) - 0xFFFFFFFFFFFFFF.

start()

void PIT_LifetimeTimer::start ( )

inline

Starts the timers for down counting.

stop()

void PIT_LifetimeTimer::stop ( )

inline

Stops the timers from counting. The timers values will freeze.

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

• code/hardware/lifetime_timer.hpp