Direct-Access

Low-level timer driver More...

Functions
int	timer_prime (int channel, uint32_t speed, int interrupts)
	Pre-initialize a timer channel, but do not start it.
int	timer_start (int channel)
	Start a timer channel.
int	timer_stop (int channel)
	Stop a timer channel.
int	timer_running (int channel)
	Checks whether a timer channel is running.
uint32_t	timer_count (int channel)
	Obtain the count of a timer channel.
int	timer_clear (int channel)
	Clear the underflow bit of a timer channel.
void	timer_enable_ints (int channel)
	Enable high-priority timer interrupts.
void	timer_disable_ints (int channel)
	Disable timer interrupts.
int	timer_ints_enabled (int channel)
	Check whether interrupts are enabled on a timer channel.

Detailed Description

Low-level timer driver

This API provides a low-level driver abstraction around the TMU peripheral and the control, counter, and reload registers of its 3 channels.

Note

You typically want to use the higher-level APIs associated with the functionality implemented by each timer channel.

Function Documentation

timer_clear()

int timer_clear

(

int

channel

)

Clear the underflow bit of a timer channel.

This function clears the underflow bit of a timer channel if it was set.

Parameters

channel

The timer channel to clear (Channels).

Return values

0	If the underflow bit was clear (prior to calling).
1	If the underflow bit was set (prior to calling).

timer_count()

uint32_t timer_count

(

int

channel

)

Obtain the count of a timer channel.

This function simply returns the count of the timer channel.

Parameters

channel

The timer channel to inspect (Channels).

Returns

The timer's count.

timer_disable_ints()

void timer_disable_ints

(

int

channel

)

Disable timer interrupts.

This function disables interrupts on the specified timer channel.

Parameters

channel

The timer channel to disable interrupts on (Channels).

timer_enable_ints()

void timer_enable_ints

(

int

channel

)

Enable high-priority timer interrupts.

This function enables interrupts on the specified timer.

Parameters

channel

The timer channel to enable interrupts on (Channels).

timer_ints_enabled()

int timer_ints_enabled

(

int

channel

)

Check whether interrupts are enabled on a timer channel.

This function checks whether or not interrupts are enabled on the specified timer channel.

Parameters

channel

The timer channel to inspect (Channels).

Return values

0	If interrupts are disabled on the timer.
1	If interrupts are enabled on the timer.

timer_prime()

int timer_prime	(	int	channel,
		uint32_t	speed,
		int	interrupts )

Pre-initialize a timer channel, but do not start it.

This function sets up a timer channel for use, but does not start it.

Parameters

channel	The timer channel to set up (Channels).
speed	The number of ticks per second.
interrupts	Set to 1 to receive interrupts when the timer ticks.

Return values

0	On success.

timer_running()

int timer_running

(

int

channel

)

Checks whether a timer channel is running.

This function checks whether the given timer channel is actively counting.

Parameters

channel

The timer channel to check (Channels).

Return values

0	The timer channel is stopped.
1	The timer channel is running.

timer_start()

int timer_start

(

int

channel

)

Start a timer channel.

This function starts a timer channel that has been initialized with timer_prime(), starting raising interrupts if applicable.

Parameters

channel

The timer channel to start (Channels).

Return values

0	On success.

timer_stop()

int timer_stop

(

int

channel

)

Stop a timer channel.

This function stops a timer channel that was started with timer_start(), and as a result stops interrupts coming in from the timer.

Parameters

channel

The timer channel to stop (Channels).

Return values

0	On success.