Timer/Counter Peripheral. More...

#include <stdint.h>
#include <stdbool.h>
#include "sam.h"
#include "system.h"

Enumerations
enum	tc_prescaler_value_t { TC_PRESCALER_DIV1 = 0 , TC_PRESCALER_DIV2 = 1 , TC_PRESCALER_DIV4 = 2 , TC_PRESCALER_DIV8 = 3 , TC_PRESCALER_DIV16 = 4 , TC_PRESCALER_DIV64 = 5 , TC_PRESCALER_DIV256 = 6 , TC_PRESCALER_DIV1024 = 7 }

enum	tc_counter_mode_t { TC_COUNTER_MODE_16BIT = 0 , TC_COUNTER_MODE_8BIT = 1 , TC_COUNTER_MODE_32BIT = 2 }

enum	tc_wavegen_t { TC_WAVEGEN_NORMAL_FREQUENCY = 0 , TC_WAVEGEN_MATCH_FREQUENCY = 1 , TC_WAVEGEN_NORMAL_PWM = 2 , TC_WAVEGEN_MATCH_PWM = 3 }

enum	tc_channel_polarity_t { TC_CHANNEL_POLARITY_NORMAL = 0 , TC_CHANNEL_POLARITY_INVERTED = 1 }

Functions
bool	tc_init (uint8_t instance, generic_clock_generator_t clocksource, tc_prescaler_value_t prescaler)
	Enables the peripheral clock for the TC and clocks it with the selected clock source. Also resets the TC to its starting configuration, which is COUNT16 mode. More...

void	tc_set_counter_mode (uint8_t instance, tc_counter_mode_t mode)
	Sets the TC's counting mode (an 8, 16 or 32-bit counter),. More...

void	tc_set_run_in_standby (uint8_t instance, bool runStandby)
	Sets the TC's run-in-standby mode. More...

void	tc_set_wavegen (uint8_t instance, tc_wavegen_t mode)
	Sets the TC's waveform generation mode. More...

void	tc_set_channel_polarity (uint8_t instance, uint8_t channel, tc_channel_polarity_t polarity)
	Sets the polarity of one of the waveform output channels. More...

void	tc_enable (uint8_t instance)
	Enables the TC. Make sure to call tc_init first to set it up. More...

bool	tc_is_enabled (uint8_t instance)
	Checks whether the TC is enabled. More...

void	tc_count8_set_period (uint8_t instance, uint8_t period)
	Sets the TC's period or PER register in 8-bit mode. More...

void	tc_count8_set_cc (uint8_t instance, uint8_t channel, uint8_t value)
	Sets the TC's compare channel CC0 or CC1 register in 8-bit mode. More...

void	tc_count16_set_cc (uint8_t instance, uint8_t channel, uint16_t value)
	Sets the TC's compare channel CC0 or CC1 register in 16-bit mode. More...

void	tc_count32_set_cc (uint8_t instance, uint8_t channel, uint32_t value)
	Sets the TC's compare channel CC0 or CC1 register in 32-bit mode. More...

void	tc_count8_set_count (uint8_t instance, uint8_t value)
	Sets the TC's counter value in 8-bit mode. More...

void	tc_count16_set_count (uint8_t instance, uint16_t value)
	Sets the TC's counter value in 16-bit mode. More...

void	tc_count32_set_count (uint8_t instance, uint32_t value)
	Sets the TC's counter value in 32-bit mode. More...

uint8_t	tc_count8_get_count (uint8_t instance)
	Gets the TC's current counter value in 8-bit mode. More...

uint16_t	tc_count16_get_count (uint8_t instance)
	Gets the TC's current counter value in 16-bit mode. More...

uint32_t	tc_count32_get_count (uint8_t instance)
	Gets the TC's current counter value in 32-bit mode. More...

void	tc_stop (uint8_t instance)
	Issues a STOP command to the TC. More...

void	tc_retrigger (uint8_t instance)
	Issues a RETRIGGER command to the TC. More...

void	tc_disable (uint8_t instance)
	Disables the TC, but retains all its settings. More...

Detailed Description

Timer/Counter Peripheral.

Function Documentation

◆ tc_count16_get_count()

uint16_t tc_count16_get_count ( uint8_t instance )

Gets the TC's current counter value in 16-bit mode.

It is possible to change the counter value when the counter is stopped or when it is running.

Parameters

instance	The TC peripheral instance as numbered in the data sheet.
value	The value to set.

◆ tc_count16_set_cc()

void tc_count16_set_cc	(	uint8_t	instance,
		uint8_t	channel,
		uint16_t	value
	)

Sets the TC's compare channel CC0 or CC1 register in 16-bit mode.

Parameters

instance	The TC peripheral instance as numbered in the data sheet.
channel	The compare channel whose value set. This value must be 0 or 1.
value	The value to set. This value must be between 0 and 65535, inclusive. Used above as described in `tc_set_wavegen`.

◆ tc_count16_set_count()

void tc_count16_set_count	(	uint8_t	instance,
		uint16_t	value
	)

Sets the TC's counter value in 16-bit mode.

It is possible to change the counter value when the counter is stopped or when it is running.

Parameters

instance	The TC peripheral instance as numbered in the data sheet.
value	The value to set.

◆ tc_count32_get_count()

uint32_t tc_count32_get_count ( uint8_t instance )

Gets the TC's current counter value in 32-bit mode.

Parameters

instance	The TC peripheral instance as numbered in the data sheet.
value	The value to set.

◆ tc_count32_set_cc()

void tc_count32_set_cc	(	uint8_t	instance,
		uint8_t	channel,
		uint32_t	value
	)

Sets the TC's compare channel CC0 or CC1 register in 32-bit mode.

Parameters

instance	The TC peripheral instance as numbered in the data sheet.
channel	The compare channel whose value set. This value must be 0 or 1.
value	The value to set.

◆ tc_count32_set_count()

void tc_count32_set_count	(	uint8_t	instance,
		uint32_t	value
	)

Sets the TC's counter value in 32-bit mode.

Parameters

instance	The TC peripheral instance as numbered in the data sheet.
value	The value to set.

◆ tc_count8_get_count()

uint8_t tc_count8_get_count ( uint8_t instance )

Gets the TC's current counter value in 8-bit mode.

Parameters

instance	The TC peripheral instance as numbered in the data sheet.
value	The value to set.

◆ tc_count8_set_cc()

void tc_count8_set_cc	(	uint8_t	instance,
		uint8_t	channel,
		uint8_t	value
	)

Sets the TC's compare channel CC0 or CC1 register in 8-bit mode.

Parameters

instance	The TC peripheral instance as numbered in the data sheet.
channel	The compare channel whose value set. This value must be 0 or 1.
value	The value to set. This value must be between 0 and 255, inclusive. Used above as described in `tc_set_wavegen`.

◆ tc_count8_set_count()

void tc_count8_set_count	(	uint8_t	instance,
		uint8_t	value
	)

Sets the TC's counter value in 8-bit mode.

Parameters

instance	The TC peripheral instance as numbered in the data sheet.
value	The value to set.

◆ tc_count8_set_period()

void tc_count8_set_period	(	uint8_t	instance,
		uint8_t	period
	)

Sets the TC's period or PER register in 8-bit mode.

Parameters

instance	The TC peripheral instance as numbered in the data sheet.
period	The period to set. This value must be between 0 and 255, inclusive. Used above as described in `tc_set_wavegen`.

◆ tc_disable()

void tc_disable ( uint8_t instance )

Disables the TC, but retains all its settings.

Parameters

instance The TC peripheral instance as numbered in the data sheet, or 0.

◆ tc_enable()

void tc_enable ( uint8_t instance )

Enables the TC. Make sure to call tc_init first to set it up.

Parameters

instance The TC peripheral instance as numbered in the data sheet, or 0.

◆ tc_init()

bool tc_init	(	uint8_t	instance,
		generic_clock_generator_t	clocksource,
		tc_prescaler_value_t	prescaler
	)

Enables the peripheral clock for the TC and clocks it with the selected clock source. Also resets the TC to its starting configuration, which is COUNT16 mode.

This just sets up the TC in its reset state. You are still responsible for configuring it with the options you need for waveform output.

Parameters

instance	The TC peripheral instance as numbered in the data sheet.
clocksource	The generic clock source to use as the TC clock.
prescaler	The prescaler factor, which divides the clock source by a factor: TC_PRESCALER_DIV1 - clock source unchanged TC_PRESCALER_DIV2 - clock source divided by 2 TC_PRESCALER_DIV4 - clock source divided by 4 TC_PRESCALER_DIV8 - clock source divided by 8 TC_PRESCALER_DIV16 - clock source divided by 16 TC_PRESCALER_DIV64 - clock source divided by 64 TC_PRESCALER_DIV256 - clock source divided by 256 TC_PRESCALER_DIV102 - clock source divided by 1024

Returns: true if the TC was set up, false if instance was out of range (i.e. you asked for TC3, but the microcontroller only has two TCs).

Note: if this function returns false, you shouldn't interact with this TC instance with any other functions; they don't do the bounds check that this does.

◆ tc_is_enabled()

bool tc_is_enabled ( uint8_t instance )

Checks whether the TC is enabled.

Parameters

instance The TC peripheral instance as numbered in the data sheet, or 0.

Returns: true if the TC is enabled, false if instance is disabled.

◆ tc_retrigger()

void tc_retrigger ( uint8_t instance )

Issues a RETRIGGER command to the TC.

When the command is detected during counting operation, the counter will be reset. When the re-trigger command is detected while the counter is stopped, the counter will resume counting from its current value.

Parameters

instance The TC peripheral instance as numbered in the data sheet.

◆ tc_set_channel_polarity()

void tc_set_channel_polarity	(	uint8_t	instance,
		uint8_t	channel,
		tc_channel_polarity_t	polarity
	)

Sets the polarity of one of the waveform output channels.

Parameters

instance	The TC peripheral instance as numbered in the data sheet.
channel	The waveform output channel. 0 or 1
polarity	The polarity to set. One of: TCC_CHANNEL_POLARITY_NORMAL - The output is high when WO[n] is set. TCC_CHANNEL_POLARITY_INVERTED - The output is low when WO[n] is set. This function can be used to invert one or both of the waveform outputs. Inverting one of the waveform outputs is useful to drive a device with a differential signal; inverting both outputs can be useful if you are driving something whose polarity is reversed, like a common anode LED.

◆ tc_set_counter_mode()

void tc_set_counter_mode	(	uint8_t	instance,
		tc_counter_mode_t	mode
	)

Sets the TC's counting mode (an 8, 16 or 32-bit counter),.

In addition to setting the maximum value the counter can count to (MAX), this mode also affects the the available registers and the register layout. As a result, you must use the correctly prefixed function calls to set CC and PER values, depending on the mode set here.

Parameters

instance The TC peripheral instance as numbered in the data sheet.

mode

The counting mode to set:

TC_MODE_16 is the default and has a MAX value of 65,535. The CC0 and CC1 registers can accept values from 0-65535, and can be set using the tc_count16_set_cc function.
TC_COUNTER_MODE_8BIT has a MAX value of 255. The CC0 and CC1 registers can accept values from 0-255, and can be set using the tc_count8_set_cc function. This mode also gives you access to a PER register that can set the period. The PER register can be set using tc_count8_set_period.
TC_COUNTER_MODE_32BIT has a MAX value of 4294967295, and is more complex as it involves ganging the TC with an adjacent TC. This mode is not fully supported or tested, and may require additional setup.

◆ tc_set_run_in_standby()

void tc_set_run_in_standby	(	uint8_t	instance,
		bool	runStandby
	)

Sets the TC's run-in-standby mode.

Parameters

instance	The TC peripheral instance as numbered in the data sheet.
runStandby	true if the TC should keep running in standby mode, false if not.

◆ tc_set_wavegen()

void tc_set_wavegen	(	uint8_t	instance,
		tc_wavegen_t	mode
	)

Sets the TC's waveform generation mode.

This function influences how the waveform is generated by determining what happens when the counter matches and overflows.

Parameters

instance The TC peripheral instance as numbered in the data sheet.

mode

The waveform generation mode to set:

TC_WAVEGEN_NORMAL_FREQUENCY - Normal frequency generation. The TOP value is either PER (in 8-bit mode) or MAX (in 16-bit mode). Waveform output WO[0] / WO[1] toggles on a match with CC0 / CC1, and the counter resets at TOP.
TC_WAVEGEN_MATCH_FREQUENCY - Match frequency generation. The TOP value is CC0. WO[0] toggles on a match with TOP / CC0 and the counter resets. This results in a square wave with a 50% duty cycle whose frequency depends on CC0. It is also useful for creating a timer that overflows at a specific frequency for generating interrupts or triggering DMA requests.
TC_WAVEGEN_NORMAL_PWM - Normal pulse-width modulation. The TOP value is either PER (in 8-bit mode) or MAX (in 16-bit mode). Waveform output WO[0] / WO[1] is set on a match with CC0 / CC1, and cleared on a match with TOP. This results in a pair of square waves whose duty cycles are determined by CC0 / CC1.
TC_WAVEGEN_MATCH_PWM - Match pulse-width modulation. The TOP value is CC0. WO[1] toggles on a match with CC1, and WO[0] emits a one-clock-wide pulse on every overflow (i.e. when the counter matches CC0 and loops). This results in a square wave on WO[1] whose period depends on CC0 and whose duty cycle depends on CC1, and a series of pulses on WO[0] that occurs at the same period.

◆ tc_stop()

void tc_stop ( uint8_t instance )

Issues a STOP command to the TC.

When a Stop is detected while the counter is running, the counter will retain its current value. All waveforms are cleared and the Stop bit in the Status register is set (STATUS.STOP).

Parameters

instance The TC peripheral instance as numbered in the data sheet.

Enumerations

Functions

Detailed Description

Function Documentation

◆ tc_count16_get_count()

◆ tc_count16_set_cc()

◆ tc_count16_set_count()

◆ tc_count32_get_count()

◆ tc_count32_set_cc()

◆ tc_count32_set_count()

◆ tc_count8_get_count()

◆ tc_count8_set_cc()

◆ tc_count8_set_count()

◆ tc_count8_set_period()

◆ tc_disable()

◆ tc_enable()

◆ tc_init()

◆ tc_is_enabled()

◆ tc_retrigger()

◆ tc_set_channel_polarity()

◆ tc_set_counter_mode()

◆ tc_set_run_in_standby()

◆ tc_set_wavegen()

◆ tc_stop()