MityDSP::tcDspCounter Class Reference

The tcDspCounter class is used to interface to the MityDSP event counter core. More...

#include <core/DspCounter.h>

List of all members.

Public Types
typedef void(*	tfIsrCallback )(int)
	prototype for the ISR callbacks.
typedef void(*	tfIsrCallbackWithArg )(int, void *)
Public Member Functions
	tcDspCounter (void *apBaseAddr, int anLevel=gnAutoLevel)
	This constructor is used to create an interface to the MityDSP counter core located at the specified base address.
	~tcDspCounter ()
	This destructor is used to close up and free tcDspCounter resources.
unsigned int	getCount (int anCounter)
	Gets the current value of the specified counter.
void	setCount (int anCounter, unsigned int anNewCount)
	Sets the current value of the specified counter.
unsigned int	getCounterDepth (int anCounter)
	Gets the current depth setting of the specified counter.
void	setCounterDepth (int anCounter, unsigned int anNewDepth, bool abReInit=false)
	Sets the depth of the specified counter.
bool	getInterruptEnable (int anCounter)
	Gets the state of the interrupt on counter rollover for the specified counter.
void	setInterruptEnable (int anCounter, bool abEnable)
	Sets the state of the interrupt on rollover for the specified counter.
void	registerIsrHandler (int anCounter, tfIsrCallback afCallback)
	Registers the user-supplied callback to be run whenever the specified counter's rollover interrupt occurs.
void	registerIsrHandler (int anCounter, tfIsrCallbackWithArg afCallback, void *apUserArg=NULL)
	Registers the user-supplied callback to be run whenever the specified counter's rollover interrupt occurs.
void	initQuadratureCount (int anCwCounter, int anCcwCounter, unsigned int anCounterDepth)
	This is a utility routine to initialize a pair of counters as a quadrature (rotation) counter.
int	getQuadratureCount (int anCwCounter, int anCcwCounter)
	This is a utility routine that returns a quadrature count based on the two provided counters (a clockwise counter and a counter-clockwise counter).
Static Public Member Functions
static int	interrupt_dispatch (Arg arMyObject)
	Static interrupt dispatch routine.
Public Attributes
unsigned int	mnInterruptCount
	ISR counter (debug).
Static Public Attributes
static const int	gnNumCounters = 16
	16 counters per core
static const unsigned int	gnMaxCounts = 0x40000000
	30-bit counters (2^30)

---

Detailed Description

The tcDspCounter class is used to interface to the MityDSP event counter core.

Up to 16 30-bit counters are provided. The counters can each be individually configured with a maximum count and to interrupt when they rollover.

Utility routines are provided to use any properly configured pair of counters as part of a quadrature counter.

See also:

tcDspCounter Page

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Member Typedef Documentation

typedef void(* MityDSP::tcDspCounter::tfIsrCallback)(int)

prototype for the ISR callbacks.

typedef void(* MityDSP::tcDspCounter::tfIsrCallbackWithArg)(int, void *)

---

Constructor & Destructor Documentation

tcDspCounter::tcDspCounter	(	void *	apAddress,
		int	anLevel = gnAutoLevel
	)

This constructor is used to create an interface to the MityDSP counter core located at the specified base address.

An interrupt level may be specified to install a chained ISR at the proper level, otherwise automatic interrupt vectoring is employed.

Parameters:

[in]	apAddress	Base Address of Counter core
[in]	anLevel	Optional interrupt level parameter

Returns:

None.

See also:

DspCounter.h

DspIntDispatch.h

tcDspCounter::~tcDspCounter

(

)

This destructor is used to close up and free tcDspCounter resources.

Returns:

None.

See also:

DspCounter.h

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Member Function Documentation

int tcDspCounter::interrupt_dispatch

(

Arg

ahMyObject

)

[static]

Static interrupt dispatch routine.

Required because of the hidden this pointer associated with a member function, which cannot be passed directly to the interrupt dispatcher.

Parameters:

[in]

ahMyObject

The "this->" pointer for the instance of tcDspCounter associated with this ISR.

Returns:

0

unsigned int tcDspCounter::getCount

(

int

anCounter

)

Gets the current value of the specified counter.

The returned value is corrected so that it is relative to the depth of the counter (i.e. for a 1024 deep counter, 0-1023 is returned rather than 2^30-1024 - 2^30-1).

Parameters:

[in]

anCounter

The counter number to read (0 - 15).

Returns:

Counter value (0 - (depth-1)).

See also:

DspCounter.h

void tcDspCounter::setCount	(	int	anCounter,
		unsigned int	anNewCount
	)

Sets the current value of the specified counter.

The provided value is relative to the current counter depth (i.e. for a 1024 deep counter, 0-1023 is provided rather than 2^30-1024 - 2^30-1).

Parameters:

[in]	anCounter	The counter number to update (0 - 15).
[in]	anNewCount	The new value (0 - (depth-1)).

Returns:

None.

See also:

DspCounter.h

unsigned int tcDspCounter::getCounterDepth

(

int

anCounter

)

Gets the current depth setting of the specified counter.

Parameters:

[in]

anCounter

The counter whose depth is being read (0 - 15).

Returns:

Counter depth (1 - 2^30).

See also:

DspCounter.h

void tcDspCounter::setCounterDepth	(	int	anCounter,
		unsigned int	anNewDepth,
		bool	abReInit = false
	)

Sets the depth of the specified counter.

Optionally resets the counter to zero (relative to the provided depth).

Parameters:

[in]	anCounter	The counter whose depth is being set (0 - 15).
[in]	anNewDepth	The new counter depth (1 - 2^30).
[in]	abReInit	Also reset counter to zero (default:false).

Returns:

None.

See also:

DspCounter.h

bool tcDspCounter::getInterruptEnable

(

int

anCounter

)

Gets the state of the interrupt on counter rollover for the specified counter.

Parameters:

[in]

anCounter

The counter whose interrupt state is being read (0 - 15).

Returns:

True if rollover interrupts are enabled, false otherwise.

See also:

DspCounter.h

void tcDspCounter::setInterruptEnable	(	int	anCounter,
		bool	abEnable
	)

Sets the state of the interrupt on rollover for the specified counter.

Parameters:

[in]	anCounter	The counter whose interrupt state is being set (0 - 15).
[in]	abEnable	True to enable rollover interrupts false otherwise.

Returns:

None.

See also:

DspCounter.h

void tcDspCounter::registerIsrHandler	(	int	anCounter,
		tfIsrCallback	afCallback
	)

Registers the user-supplied callback to be run whenever the specified counter's rollover interrupt occurs.

Caution should be used as this callback will execute in ISR context (no DSP/BIOS calls that can potentially block are allowed)

Parameters:

[in]	anCounter	The counter to install the callback for.
[in]	afCallback	Pointer to the callback routine (or NULL to disable callbacks.

Returns:

None.

See also:

DspCounter.h

void tcDspCounter::registerIsrHandler	(	int	anCounter,
		tfIsrCallbackWithArg	afCallback,
		void *	apUserArg = NULL
	)

Registers the user-supplied callback to be run whenever the specified counter's rollover interrupt occurs.

Caution should be used as this callback will execute in ISR context (no DSP/BIOS calls that can potentially block are allowed)

Parameters:

[in]	anCounter	The counter to install the callback for.
[in]	afCallback	Pointer to the callback routine (or NULL to disable callbacks.
[in]	apUserArg	An argument to be supplied with the callback.

Returns:

None.

See also:

DspCounter.h

void tcDspCounter::initQuadratureCount	(	int	anCwCounter,
		int	anCcwCounter,
		unsigned int	anCounterDepth
	)

This is a utility routine to initialize a pair of counters as a quadrature (rotation) counter.

A "clockwise" and a "counter-clockwise" counter are provided. Both are set to the provided counter depth and reinitialized.

Parameters:

[in]	anCwCounter	The CW quadrature counter.
[in]	anCcwCounter	The CCW quadrature counter.
[in]	anCounterDepth	The depth to set both counters to.

Returns:

None.

See also:

DspCounter.h

int tcDspCounter::getQuadratureCount	(	int	anCwCounter,
		int	anCcwCounter
	)

This is a utility routine that returns a quadrature count based on the two provided counters (a clockwise counter and a counter-clockwise counter).

These counters should have been previously initialized using initQuadratureCount.

The returned value represents the number of rotations since initialization.

Note:

It is up to the application to handle rollover conditions. The recommended method to do this is to either set the depth of the counters such that rollover is not possible, or if this is not practical, periodically call initQuadratureCount to reset the counters while retaining the previous total rotation count.

Parameters:

[in]	anCwCounter	The CW quadrature counter.
[in]	anCcwCounter	The CCW quadrature counter.

Returns:

Rotation count (CW is positive).

See also:

DspCounter.h

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Member Data Documentation

const int MityDSP::tcDspCounter::gnNumCounters = 16 [static]

16 counters per core

const unsigned int MityDSP::tcDspCounter::gnMaxCounts = 0x40000000 [static]

30-bit counters (2^30)

unsigned int MityDSP::tcDspCounter::mnInterruptCount

ISR counter (debug).