Collaboration diagram for ICU Driver:

Detailed Description

Generic ICU Driver.

This module implements a generic ICU (Input Capture Unit) driver.

Precondition:: In order to use the ICU driver the HAL_USE_ICU option must be enabled in halconf.h.

Driver State Machine

The driver implements a state machine internally, not all the driver functionalities can be used in any moment, any transition not explicitly shown in the following diagram has to be considered an error and shall be captured by an assertion (if enabled).

ICU Operations.

This driver abstracts a generic Input Capture Unit composed of:

A clock prescaler.
A main up counter.
Two capture registers triggered by the rising and falling edges on the sampled input.

The ICU unit can be programmed to synchronize on the rising or falling edge of the sample input:

ICU_INPUT_ACTIVE_HIGH, a rising edge is the start signal.
ICU_INPUT_ACTIVE_LOW, a falling edge is the start signal.

After the activation the ICU unit can be in one of the following states at any time:

ICU_WAITING, waiting the first start signal.
ICU_ACTIVE, after a start signal.
ICU_IDLE, after a stop signal.

Callbacks are invoked when start or stop signals occur.

Functions
void	icuInit (void)
	ICU Driver initialization.
void	icuObjectInit (ICUDriver *icup)
	Initializes the standard part of a `ICUDriver` structure.
void	icuStart (ICUDriver icup, const ICUConfig config)
	Configures and activates the ICU peripheral.
void	icuStop (ICUDriver *icup)
	Deactivates the ICU peripheral.
void	icuEnable (ICUDriver *icup)
	Enables the input capture.
void	icuDisable (ICUDriver *icup)
	Disables the input capture.
Macro Functions
#define	icuEnableI(icup) icu_lld_enable(icup)
	Enables the input capture.
#define	icuDisableI(icup) icu_lld_disable(icup)
	Disables the input capture.
#define	icuGetWidth(icup) icu_lld_get_width(icup)
	Returns the width of the latest pulse.
#define	icuGetPeriod(icup) icu_lld_get_period(icup)
	Returns the width of the latest cycle.
Low Level driver helper macros
#define	_icu_isr_invoke_width_cb(icup)
	Common ISR code, ICU width event.
#define	_icu_isr_invoke_period_cb(icup)
	Common ISR code, ICU period event.
#define	_icu_isr_invoke_overflow_cb(icup)
	Common ISR code, ICU timer overflow event.
Typedefs
typedef struct ICUDriver	ICUDriver
	Type of a structure representing an ICU driver.
typedef void(*	icucallback_t )(ICUDriver *icup)
	ICU notification callback type.
Enumerations
enum	icustate_t { ICU_UNINIT = 0, ICU_STOP = 1, ICU_READY = 2, ICU_WAITING = 3, ICU_ACTIVE = 4, ICU_IDLE = 5 }
	Driver state machine possible states. More...

Function Documentation

void icuInit ( void )

ICU Driver initialization.

Note:: This function is implicitly invoked by halInit(), there is no need to explicitly initialize the driver.

Function Class:: Initializer, this function just initializes an object and can be invoked before the kernel is initialized.

Definition at line 61 of file icu.c.

Referenced by halInit().

void icuObjectInit ( ICUDriver * icup )

Initializes the standard part of a ICUDriver structure.

Parameters:

[out] icup pointer to the ICUDriver object

Function Class:: Initializer, this function just initializes an object and can be invoked before the kernel is initialized.

Definition at line 73 of file icu.c.

References ICU_STOP.

void icuStart	(	ICUDriver *	icup,
		const ICUConfig *	config
	)

Configures and activates the ICU peripheral.

Parameters:

[in]	icup	pointer to the `ICUDriver` object
[in]	config	pointer to the `ICUConfig` object

Function Class:: Normal API, this function can be invoked by regular system threads but not from within a lock zone.

Definition at line 87 of file icu.c.

References chDbgAssert, chDbgCheck, chSysLock, chSysUnlock, ICU_READY, and ICU_STOP.

void icuStop ( ICUDriver * icup )

Deactivates the ICU peripheral.

Parameters:

[in] icup pointer to the ICUDriver object

Function Class:: Normal API, this function can be invoked by regular system threads but not from within a lock zone.

Definition at line 107 of file icu.c.

References chDbgAssert, chDbgCheck, chSysLock, chSysUnlock, ICU_READY, and ICU_STOP.

void icuEnable ( ICUDriver * icup )

Enables the input capture.

Parameters:

[in] icup pointer to the ICUDriver object

Function Class:: Normal API, this function can be invoked by regular system threads but not from within a lock zone.

Definition at line 126 of file icu.c.

References chDbgAssert, chDbgCheck, chSysLock, chSysUnlock, ICU_READY, and ICU_WAITING.

void icuDisable ( ICUDriver * icup )

Disables the input capture.

Parameters:

[in] icup pointer to the ICUDriver object

Function Class:: Normal API, this function can be invoked by regular system threads but not from within a lock zone.

Definition at line 144 of file icu.c.

References chDbgAssert, chDbgCheck, chSysLock, chSysUnlock, ICU_ACTIVE, ICU_IDLE, ICU_READY, and ICU_WAITING.

Define Documentation

#define icuEnableI ( icup ) icu_lld_enable(icup)

Enables the input capture.

Parameters:

[in] icup pointer to the ICUDriver object

Function Class:: This is an I-Class API, this function can be invoked from within a system lock zone by both threads and interrupt handlers.

Definition at line 91 of file icu.h.

#define icuDisableI ( icup ) icu_lld_disable(icup)

Disables the input capture.

Parameters:

[in] icup pointer to the ICUDriver object

Function Class:: This is an I-Class API, this function can be invoked from within a system lock zone by both threads and interrupt handlers.

Definition at line 100 of file icu.h.

#define icuGetWidth ( icup ) icu_lld_get_width(icup)

Returns the width of the latest pulse.

The pulse width is defined as number of ticks between the start edge and the stop edge.

Note:: This function is meant to be invoked from the width capture callback only.

Parameters:

[in] icup pointer to the ICUDriver object

Returns:: The number of ticks.

Function Class:: Special function, this function has special requirements see the notes.

Definition at line 114 of file icu.h.

#define icuGetPeriod ( icup ) icu_lld_get_period(icup)

Returns the width of the latest cycle.

The cycle width is defined as number of ticks between a start edge and the next start edge.

Note:: This function is meant to be invoked from the width capture callback only.

Parameters:

[in] icup pointer to the ICUDriver object

Returns:: The number of ticks.

Function Class:: Special function, this function has special requirements see the notes.

Definition at line 128 of file icu.h.

#define _icu_isr_invoke_width_cb ( icup )

Value:

{                                    \
  (icup)->state = ICU_IDLE;                                                 \
  (icup)->config->width_cb(icup);                                           \
}

Common ISR code, ICU width event.

Parameters:

[in] icup pointer to the ICUDriver object

Function Class:: Not an API, this function is for internal use only.

Definition at line 142 of file icu.h.

#define _icu_isr_invoke_period_cb ( icup )

Value:

{                                   \
  icustate_t previous_state = (icup)->state;                                \
  (icup)->state = ICU_ACTIVE;                                               \
  if (previous_state != ICU_WAITING)                                        \
    (icup)->config->period_cb(icup);                                        \
}

Common ISR code, ICU period event.

Parameters:

[in] icup pointer to the ICUDriver object

Function Class:: Not an API, this function is for internal use only.

Definition at line 154 of file icu.h.

#define _icu_isr_invoke_overflow_cb ( icup )

Value:

{                                 \
  (icup)->config->overflow_cb(icup);                                        \
}

Common ISR code, ICU timer overflow event.

Parameters:

[in] icup pointer to the ICUDriver object

Function Class:: Not an API, this function is for internal use only.

Definition at line 168 of file icu.h.

Typedef Documentation

typedef struct ICUDriver ICUDriver

Type of a structure representing an ICU driver.

Definition at line 65 of file icu.h.

typedef void(* icucallback_t)(ICUDriver *icup)

ICU notification callback type.

Parameters:

[in] icup pointer to a ICUDriver object

Definition at line 72 of file icu.h.

Enumeration Type Documentation

enum icustate_t

Driver state machine possible states.

Enumerator:

ICU_UNINIT	Not initialized.
ICU_STOP	Stopped.
ICU_READY	Ready.
ICU_WAITING	Waiting first edge.
ICU_ACTIVE	Active cycle phase.
ICU_IDLE	Idle cycle phase.

Definition at line 53 of file icu.h.

Detailed Description

Driver State Machine

ICU Operations.

Functions

Macro Functions

Low Level driver helper macros

Typedefs

Enumerations

Function Documentation

Define Documentation

Typedef Documentation

Enumeration Type Documentation