Overview

The MCUXpresso SDK provides a driver for the ctimer module of MCUXpresso SDK devices.

Function groups

The ctimer driver supports the generation of PWM signals, input capture and setting up the timer match conditions.

Initialization and deinitialization

The function CTIMER_Init() initializes the ctimer with specified configurations. The function CTIMER_GetDefaultConfig() gets the default configurations. The initialization function configures the counter/timer mode and input selection when running in counter mode.

The function CTIMER_Deinit() stops the timer and turns off the module clock.

PWM Operations

The function CTIMER_SetupPwm() sets up channels for PWM output. Each channel has its own duty cycle, however the same PWM period is applied to all channels requesting the PWM output. The signal duty cycle is provided as a percentage of the PWM period. Its value should be between 0 and 100 0=inactive signal(0% duty cycle) and 100=always active signal (100% duty cycle).

The function CTIMER_UpdatePwmDutycycle() updates the PWM signal duty cycle of a particular channel.

Match Operation

The function CTIMER_SetupMatch() sets up channels for match operation. Each channel is configured with a match value, if the counter should stop on match, if counter should reset on match and output pin action. The output signal can be cleared, set or toggled on match.

Input capture operations

The function CTIMER_SetupCapture() sets up an channel for input capture. The user can specify the capture edge and if a interrupt should be generated when processing the input signal.

Typical use case

Match example

Set up a match channel to toggle output when a match occurs. Refer to the driver examples codes located at <SDK_ROOT>/boards/<BOARD>/driver_examples/ctimer

PWM output example

Set up a channel for PWM output. Refer to the driver examples codes located at <SDK_ROOT>/boards/<BOARD>/driver_examples/ctimer

Files
file	fsl_ctimer.h

Data Structures
struct	ctimer_match_config_t
	Match configuration. More...

struct	ctimer_config_t
	Timer configuration structure. More...

Enumerations
enum	ctimer_capture_channel_t { kCTIMER_Capture_0 = 0U, kCTIMER_Capture_1, kCTIMER_Capture_2 }
	List of Timer capture channels. More...

enum	ctimer_capture_edge_t { kCTIMER_Capture_RiseEdge = 1U, kCTIMER_Capture_FallEdge = 2U, kCTIMER_Capture_BothEdge = 3U }
	List of capture edge options. More...

enum	ctimer_match_t { kCTIMER_Match_0 = 0U, kCTIMER_Match_1, kCTIMER_Match_2, kCTIMER_Match_3 }
	List of Timer match registers. More...

enum	ctimer_match_output_control_t { kCTIMER_Output_NoAction = 0U, kCTIMER_Output_Clear, kCTIMER_Output_Set, kCTIMER_Output_Toggle }
	List of output control options. More...

enum	ctimer_timer_mode_t
	List of Timer modes.

enum	ctimer_interrupt_enable_t { kCTIMER_Match0InterruptEnable = CTIMER_MCR_MR0I_MASK, kCTIMER_Match1InterruptEnable = CTIMER_MCR_MR1I_MASK, kCTIMER_Match2InterruptEnable = CTIMER_MCR_MR2I_MASK, kCTIMER_Match3InterruptEnable = CTIMER_MCR_MR3I_MASK, kCTIMER_Capture0InterruptEnable = CTIMER_CCR_CAP0I_MASK, kCTIMER_Capture1InterruptEnable = CTIMER_CCR_CAP1I_MASK, kCTIMER_Capture2InterruptEnable = CTIMER_CCR_CAP2I_MASK }
	List of Timer interrupts. More...

enum	ctimer_status_flags_t { kCTIMER_Match0Flag = CTIMER_IR_MR0INT_MASK, kCTIMER_Match1Flag = CTIMER_IR_MR1INT_MASK, kCTIMER_Match2Flag = CTIMER_IR_MR2INT_MASK, kCTIMER_Match3Flag = CTIMER_IR_MR3INT_MASK, kCTIMER_Capture0Flag = CTIMER_IR_CR0INT_MASK, kCTIMER_Capture1Flag = CTIMER_IR_CR1INT_MASK, kCTIMER_Capture2Flag = CTIMER_IR_CR2INT_MASK }
	List of Timer flags. More...

enum	ctimer_callback_type_t { kCTIMER_SingleCallback, kCTIMER_MultipleCallback }
	Callback type when registering for a callback. More...

Functions
void	CTIMER_SetupMatch (CTIMER_Type base, ctimer_match_t matchChannel, const ctimer_match_config_t config)
	Setup the match register. More...

void	CTIMER_SetupCapture (CTIMER_Type *base, ctimer_capture_channel_t capture, ctimer_capture_edge_t edge, bool enableInt)
	Setup the capture. More...

void	CTIMER_RegisterCallBack (CTIMER_Type base, ctimer_callback_t cb_func, ctimer_callback_type_t cb_type)
	Register callback. More...

static void	CTIMER_Reset (CTIMER_Type *base)
	Reset the counter. More...

Driver version
#define	FSL_CTIMER_DRIVER_VERSION (MAKE_VERSION(2, 0, 0))
	Version 2.0.0.

Initialization and deinitialization
void	CTIMER_Init (CTIMER_Type base, const ctimer_config_t config)
	Ungates the clock and configures the peripheral for basic operation. More...

void	CTIMER_Deinit (CTIMER_Type *base)
	Gates the timer clock. More...

void	CTIMER_GetDefaultConfig (ctimer_config_t *config)
	Fills in the timers configuration structure with the default settings. More...

PWM setup operations
status_t	CTIMER_SetupPwm (CTIMER_Type *base, ctimer_match_t matchChannel, uint8_t dutyCyclePercent, uint32_t pwmFreq_Hz, uint32_t srcClock_Hz, bool enableInt)
	Configures the PWM signal parameters. More...

void	CTIMER_UpdatePwmDutycycle (CTIMER_Type *base, ctimer_match_t matchChannel, uint8_t dutyCyclePercent)
	Updates the duty cycle of an active PWM signal. More...

Interrupt Interface
static void	CTIMER_EnableInterrupts (CTIMER_Type *base, uint32_t mask)
	Enables the selected Timer interrupts. More...

static void	CTIMER_DisableInterrupts (CTIMER_Type *base, uint32_t mask)
	Disables the selected Timer interrupts. More...

static uint32_t	CTIMER_GetEnabledInterrupts (CTIMER_Type *base)
	Gets the enabled Timer interrupts. More...

Status Interface
static uint32_t	CTIMER_GetStatusFlags (CTIMER_Type *base)
	Gets the Timer status flags. More...

static void	CTIMER_ClearStatusFlags (CTIMER_Type *base, uint32_t mask)
	Clears the Timer status flags. More...

Counter Start and Stop
static void	CTIMER_StartTimer (CTIMER_Type *base)
	Starts the Timer counter. More...

static void	CTIMER_StopTimer (CTIMER_Type *base)
	Stops the Timer counter. More...

Data Structure Documentation

struct ctimer_match_config_t

This structure holds the configuration settings for each match register.

Data Fields
uint32_t	matchValue
	This is stored in the match register.

bool	enableCounterReset
	true: Match will reset the counter false: Match will not reser the counter

bool	enableCounterStop
	true: Match will stop the counter false: Match will not stop the counter

ctimer_match_output_control_t	outControl
	Action to be taken on a match on the EM bit/output.

bool	outPinInitState
	Initial value of the EM bit/output.

bool	enableInterrupt
	true: Generate interrupt upon match false: Do not generate interrupt on match

struct ctimer_config_t

This structure holds the configuration settings for the Timer peripheral. To initialize this structure to reasonable defaults, call the CTIMER_GetDefaultConfig() function and pass a pointer to the configuration structure instance.

The configuration structure can be made constant so as to reside in flash.

Data Fields
ctimer_timer_mode_t	mode
	Timer mode.

ctimer_capture_channel_t	input
	Input channel to increment the timer, used only in timer modes that rely on this input signal to increment TC.

uint32_t	prescale
	Prescale value.

Enumeration Type Documentation

enum ctimer_capture_channel_t

Enumerator
kCTIMER_Capture_0	Timer capture channel 0.
kCTIMER_Capture_1	Timer capture channel 1.
kCTIMER_Capture_2	Timer capture channel 2.

enum ctimer_capture_edge_t

Enumerator
kCTIMER_Capture_RiseEdge	Capture on rising edge.
kCTIMER_Capture_FallEdge	Capture on falling edge.
kCTIMER_Capture_BothEdge	Capture on rising and falling edge.

enum ctimer_match_t

Enumerator
kCTIMER_Match_0	Timer match register 0.
kCTIMER_Match_1	Timer match register 1.
kCTIMER_Match_2	Timer match register 2.
kCTIMER_Match_3	Timer match register 3.

enum ctimer_match_output_control_t

Enumerator
kCTIMER_Output_NoAction	No action is taken.
kCTIMER_Output_Clear	Clear the EM bit/output to 0.
kCTIMER_Output_Set	Set the EM bit/output to 1.
kCTIMER_Output_Toggle	Toggle the EM bit/output.

enum ctimer_interrupt_enable_t

Enumerator
kCTIMER_Match0InterruptEnable	Match 0 interrupt.
kCTIMER_Match1InterruptEnable	Match 1 interrupt.
kCTIMER_Match2InterruptEnable	Match 2 interrupt.
kCTIMER_Match3InterruptEnable	Match 3 interrupt.
kCTIMER_Capture0InterruptEnable	Capture 0 interrupt.
kCTIMER_Capture1InterruptEnable	Capture 1 interrupt.
kCTIMER_Capture2InterruptEnable	Capture 2 interrupt.

enum ctimer_status_flags_t

Enumerator
kCTIMER_Match0Flag	Match 0 interrupt flag.
kCTIMER_Match1Flag	Match 1 interrupt flag.
kCTIMER_Match2Flag	Match 2 interrupt flag.
kCTIMER_Match3Flag	Match 3 interrupt flag.
kCTIMER_Capture0Flag	Capture 0 interrupt flag.
kCTIMER_Capture1Flag	Capture 1 interrupt flag.
kCTIMER_Capture2Flag	Capture 2 interrupt flag.

enum ctimer_callback_type_t

When registering a callback an array of function pointers is passed the size could be 1 or 8, the callback type will tell that.

Enumerator

kCTIMER_SingleCallback

Single Callback type where there is only one callback for the timer.

based on the status flags different channels needs to be handled differently

kCTIMER_MultipleCallback

Multiple Callback type where there can be 8 valid callbacks, one per channel.

for both match/capture

Function Documentation

void CTIMER_Init	(	CTIMER_Type *	base,
		const ctimer_config_t *	config
	)

Note: This API should be called at the beginning of the application before using the driver.

Parameters

base	Ctimer peripheral base address
config	Pointer to the user configuration structure.

void CTIMER_Deinit ( CTIMER_Type * base )

Parameters

base	Ctimer peripheral base address

void CTIMER_GetDefaultConfig ( ctimer_config_t * config )

The default values are:

*   config->mode = kCTIMER_TimerMode;
*   config->input = kCTIMER_Capture_0;
*   config->prescale = 0;
* 

Parameters

config Pointer to the user configuration structure.

status_t CTIMER_SetupPwm	(	CTIMER_Type *	base,
		ctimer_match_t	matchChannel,
		uint8_t	dutyCyclePercent,
		uint32_t	pwmFreq_Hz,
		uint32_t	srcClock_Hz,
		bool	enableInt
	)

Enables PWM mode on the match channel passed in and will then setup the match value and other match parameters to generate a PWM signal. This function will assign match channel 3 to set the PWM cycle.

Note: When setting PWM output from multiple output pins, all should use the same PWM frequency

Parameters

base	Ctimer peripheral base address
matchChannel	Match pin to be used to output the PWM signal
dutyCyclePercent	PWM pulse width; the value should be between 0 to 100
pwmFreq_Hz	PWM signal frequency in Hz
srcClock_Hz	Timer counter clock in Hz
enableInt	Enable interrupt when the timer value reaches the match value of the PWM pulse, if it is 0 then no interrupt is generated

Returns: kStatus_Success on success kStatus_Fail If matchChannel passed in is 3; this channel is reserved to set the PWM cycle

void CTIMER_UpdatePwmDutycycle	(	CTIMER_Type *	base,
		ctimer_match_t	matchChannel,
		uint8_t	dutyCyclePercent
	)

Parameters

base	Ctimer peripheral base address
matchChannel	Match pin to be used to output the PWM signal
dutyCyclePercent	New PWM pulse width; the value should be between 0 to 100

void CTIMER_SetupMatch	(	CTIMER_Type *	base,
		ctimer_match_t	matchChannel,
		const ctimer_match_config_t *	config
	)

User configuration is used to setup the match value and action to be taken when a match occurs.

Parameters

base	Ctimer peripheral base address
matchChannel	Match register to configure
config	Pointer to the match configuration structure

void CTIMER_SetupCapture	(	CTIMER_Type *	base,
		ctimer_capture_channel_t	capture,
		ctimer_capture_edge_t	edge,
		bool	enableInt
	)

Parameters

base	Ctimer peripheral base address
capture	Capture channel to configure
edge	Edge on the channel that will trigger a capture
enableInt	Flag to enable channel interrupts, if enabled then the registered call back is called upon capture

void CTIMER_RegisterCallBack	(	CTIMER_Type *	base,
		ctimer_callback_t *	cb_func,
		ctimer_callback_type_t	cb_type
	)

Parameters

base	Ctimer peripheral base address
cb_func	callback function
cb_type	callback function type, singular or multiple

static void CTIMER_EnableInterrupts	(	CTIMER_Type *	base,
		uint32_t	mask
	)

inlinestatic

Parameters

base	Ctimer peripheral base address
mask	The interrupts to enable. This is a logical OR of members of the enumeration ctimer_interrupt_enable_t

static void CTIMER_DisableInterrupts	(	CTIMER_Type *	base,
		uint32_t	mask
	)

inlinestatic

Parameters

base	Ctimer peripheral base address
mask	The interrupts to enable. This is a logical OR of members of the enumeration ctimer_interrupt_enable_t

static uint32_t CTIMER_GetEnabledInterrupts ( CTIMER_Type * base )

inlinestatic

Parameters

base	Ctimer peripheral base address

Returns: The enabled interrupts. This is the logical OR of members of the enumeration ctimer_interrupt_enable_t

static uint32_t CTIMER_GetStatusFlags ( CTIMER_Type * base )

inlinestatic

Parameters

base	Ctimer peripheral base address

Returns: The status flags. This is the logical OR of members of the enumeration ctimer_status_flags_t

static void CTIMER_ClearStatusFlags	(	CTIMER_Type *	base,
		uint32_t	mask
	)

inlinestatic

Parameters

base	Ctimer peripheral base address
mask	The status flags to clear. This is a logical OR of members of the enumeration ctimer_status_flags_t

static void CTIMER_StartTimer ( CTIMER_Type * base )

inlinestatic

Parameters

base	Ctimer peripheral base address

static void CTIMER_StopTimer ( CTIMER_Type * base )

inlinestatic

Parameters

base	Ctimer peripheral base address

static void CTIMER_Reset ( CTIMER_Type * base )

inlinestatic

The timer counter and prescale counter are reset on the next positive edge of the APB clock.

Parameters

base	Ctimer peripheral base address

Overview

Function groups

Initialization and deinitialization

PWM Operations

Match Operation

Input capture operations

Typical use case

Match example

PWM output example

Files

Data Structures

Enumerations

Functions

Driver version

Initialization and deinitialization

PWM setup operations

Interrupt Interface

Status Interface

Counter Start and Stop

Data Structure Documentation

Data Fields

Data Fields

Enumeration Type Documentation

Function Documentation