GPT_General_Purpose_Timer_api

Functions
void	TimerEnable (unsigned long ulBase, unsigned long ulTimer)
void	TimerDisable (unsigned long ulBase, unsigned long ulTimer)
void	TimerConfigure (unsigned long ulBase, unsigned long ulConfig)
void	TimerControlLevel (unsigned long ulBase, unsigned long ulTimer, tBoolean bInvert)
void	TimerControlEvent (unsigned long ulBase, unsigned long ulTimer, unsigned long ulEvent)
void	TimerControlStall (unsigned long ulBase, unsigned long ulTimer, tBoolean bStall)
void	TimerPrescaleSet (unsigned long ulBase, unsigned long ulTimer, unsigned long ulValue)
unsigned long	TimerPrescaleGet (unsigned long ulBase, unsigned long ulTimer)
void	TimerPrescaleMatchSet (unsigned long ulBase, unsigned long ulTimer, unsigned long ulValue)
unsigned long	TimerPrescaleMatchGet (unsigned long ulBase, unsigned long ulTimer)
void	TimerLoadSet (unsigned long ulBase, unsigned long ulTimer, unsigned long ulValue)
unsigned long	TimerLoadGet (unsigned long ulBase, unsigned long ulTimer)
unsigned long	TimerValueGet (unsigned long ulBase, unsigned long ulTimer)
void	TimerValueSet (unsigned long ulBase, unsigned long ulTimer, unsigned long ulValue)
void	TimerMatchSet (unsigned long ulBase, unsigned long ulTimer, unsigned long ulValue)
unsigned long	TimerMatchGet (unsigned long ulBase, unsigned long ulTimer)
void	TimerIntRegister (unsigned long ulBase, unsigned long ulTimer, void(*pfnHandler)(void))
void	TimerIntUnregister (unsigned long ulBase, unsigned long ulTimer)
void	TimerIntEnable (unsigned long ulBase, unsigned long ulIntFlags)
void	TimerIntDisable (unsigned long ulBase, unsigned long ulIntFlags)
unsigned long	TimerIntStatus (unsigned long ulBase, tBoolean bMasked)
void	TimerIntClear (unsigned long ulBase, unsigned long ulIntFlags)
void	TimerDMAEventSet (unsigned long ulBase, unsigned long ulDMAEvent)
unsigned long	TimerDMAEventGet (unsigned long ulBase)

Detailed Description

Function Documentation

void TimerConfigure	(	unsigned long	ulBase,
		unsigned long	ulConfig
	)

Configures the timer(s).

Parameters

ulBase	is the base address of the timer module.
ulConfig	is the configuration for the timer.

This function configures the operating mode of the timer(s). The timer module is disabled before being configured, and is left in the disabled state. The 16/32-bit timer is comprised of two 16-bit timers that can operate independently or be concatenated to form a 32-bit timer.

The configuration is specified in ulConfig as one of the following values:

• TIMER_CFG_ONE_SHOT - Full-width one-shot timer
• TIMER_CFG_ONE_SHOT_UP - Full-width one-shot timer that counts up instead of down (not available on all parts)
• TIMER_CFG_PERIODIC - Full-width periodic timer
• TIMER_CFG_PERIODIC_UP - Full-width periodic timer that counts up instead of down (not available on all parts)
• TIMER_CFG_SPLIT_PAIR - Two half-width timers

When configured for a pair of half-width timers, each timer is separately configured. The first timer is configured by setting ulConfig to the result of a logical OR operation between one of the following values and ulConfig:

• TIMER_CFG_A_ONE_SHOT - Half-width one-shot timer
• TIMER_CFG_A_ONE_SHOT_UP - Half-width one-shot timer that counts up instead of down (not available on all parts)
• TIMER_CFG_A_PERIODIC - Half-width periodic timer
• TIMER_CFG_A_PERIODIC_UP - Half-width periodic timer that counts up instead of down (not available on all parts)
• TIMER_CFG_A_CAP_COUNT - Half-width edge count capture
• TIMER_CFG_A_CAP_TIME - Half-width edge time capture
• TIMER_CFG_A_PWM - Half-width PWM output

Similarly, the second timer is configured by setting ulConfig to the result of a logical OR operation between one of the corresponding TIMER_CFG_B_* values and ulConfig.

Returns

None.

void TimerControlEvent	(	unsigned long	ulBase,
		unsigned long	ulTimer,
		unsigned long	ulEvent
	)

Controls the event type.

Parameters

ulBase	is the base address of the timer module.
ulTimer	specifies the timer(s) to be adjusted; must be one of TIMER_A, TIMER_B, or TIMER_BOTH.
ulEvent	specifies the type of event; must be one of TIMER_EVENT_POS_EDGE, TIMER_EVENT_NEG_EDGE, or TIMER_EVENT_BOTH_EDGES.

This function sets the signal edge(s) that triggers the timer when in capture mode.

Returns

None.

void TimerControlLevel	(	unsigned long	ulBase,
		unsigned long	ulTimer,
		tBoolean	bInvert
	)

Controls the output level.

Parameters

ulBase	is the base address of the timer module.
ulTimer	specifies the timer(s) to adjust; must be one of TIMER_A, TIMER_B, or TIMER_BOTH.
bInvert	specifies the output level.

This function sets the PWM output level for the specified timer. If the bInvert parameter is true, then the timer's output is made active low; otherwise, it is made active high.

Returns

None.

void TimerControlStall	(	unsigned long	ulBase,
		unsigned long	ulTimer,
		tBoolean	bStall
	)

Controls the stall handling.

Parameters

ulBase	is the base address of the timer module.
ulTimer	specifies the timer(s) to be adjusted; must be one of TIMER_A, TIMER_B, or TIMER_BOTH.
bStall	specifies the response to a stall signal.

This function controls the stall response for the specified timer. If the bStall parameter is true, then the timer stops counting if the processor enters debug mode; otherwise the timer keeps running while in debug mode.

Returns

None.

void TimerDisable	(	unsigned long	ulBase,
		unsigned long	ulTimer
	)

Disables the timer(s).

Parameters

ulBase	is the base address of the timer module.
ulTimer	specifies the timer(s) to disable; must be one of TIMER_A, TIMER_B, or TIMER_BOTH.

This function disables operation of the timer module.

Returns

None.

unsigned long TimerDMAEventGet

(

unsigned long

ulBase

)

Returns the events that can trigger a DMA request.

Parameters

ulBase

is the base address of the timer module.

This function returns the timer events that can trigger the start of a DMA sequence. The DMA trigger events are the logical OR of the following values:

• TIMER_DMA_MODEMATCH_B - Enables the mode match DMA trigger for timer B.
• TIMER_DMA_CAPEVENT_B - Enables the capture event DMA trigger for timer B.
• TIMER_DMA_CAPMATCH_B - Enables the capture match DMA trigger for timer B.
• TIMER_DMA_TIMEOUT_B - Enables the timeout DMA trigger for timer B.
• TIMER_DMA_MODEMATCH_A - Enables the mode match DMA trigger for timer A.
• TIMER_DMA_CAPEVENT_A - Enables the capture event DMA trigger for timer A.
• TIMER_DMA_CAPMATCH_A - Enables the capture match DMA trigger for timer A.
• TIMER_DMA_TIMEOUT_A - Enables the timeout DMA trigger for timer A.

Returns

The timer events that trigger the uDMA.

void TimerDMAEventSet	(	unsigned long	ulBase,
		unsigned long	ulDMAEvent
	)

Enables the events that can trigger a DMA request.

Parameters

ulBase	is the base address of the timer module.
ulDMAEvent	is a bit mask of the events that can trigger DMA.

This function enables the timer events that can trigger the start of a DMA sequence. The DMA trigger events are specified in the ui32DMAEvent parameter by passing in the logical OR of the following values:

• TIMER_DMA_MODEMATCH_B - The mode match DMA trigger for timer B is enabled.
• TIMER_DMA_CAPEVENT_B - The capture event DMA trigger for timer B is enabled.
• TIMER_DMA_CAPMATCH_B - The capture match DMA trigger for timer B is enabled.
• TIMER_DMA_TIMEOUT_B - The timeout DMA trigger for timer B is enabled.
• TIMER_DMA_MODEMATCH_A - The mode match DMA trigger for timer A is enabled.
• TIMER_DMA_CAPEVENT_A - The capture event DMA trigger for timer A is enabled.
• TIMER_DMA_CAPMATCH_A - The capture match DMA trigger for timer A is enabled.
• TIMER_DMA_TIMEOUT_A - The timeout DMA trigger for timer A is enabled.

Returns

None.

void TimerEnable	(	unsigned long	ulBase,
		unsigned long	ulTimer
	)

Enables the timer(s).

Parameters

ulBase	is the base address of the timer module.
ulTimer	specifies the timer(s) to enable; must be one of TIMER_A, TIMER_B, or TIMER_BOTH.

This function enables operation of the timer module. The timer must be configured before it is enabled.

Returns

None.

void TimerIntClear	(	unsigned long	ulBase,
		unsigned long	ulIntFlags
	)

Clears timer interrupt sources.

Parameters

ulBase	is the base address of the timer module.
ulIntFlags	is a bit mask of the interrupt sources to be cleared.

The specified timer interrupt sources are cleared, so that they no longer assert. This function must be called in the interrupt handler to keep the interrupt from being triggered again immediately upon exit.

The ulIntFlags parameter has the same definition as the ulIntFlags parameter to TimerIntEnable().

Note

Because there is a write buffer in the Cortex-M3 processor, it may take several clock cycles before the interrupt source is actually cleared. Therefore, it is recommended that the interrupt source be cleared early in the interrupt handler (as opposed to the very last action) to avoid returning from the interrupt handler before the interrupt source is actually cleared. Failure to do so may result in the interrupt handler being immediately reentered (because the interrupt controller still sees the interrupt source asserted).

Returns

None.

void TimerIntDisable	(	unsigned long	ulBase,
		unsigned long	ulIntFlags
	)

Disables individual timer interrupt sources.

Parameters

ulBase	is the base address of the timer module.
ulIntFlags	is the bit mask of the interrupt sources to be disabled.

Disables the indicated timer interrupt sources. Only the sources that are enabled can be reflected to the processor interrupt; disabled sources have no effect on the processor.

The ulIntFlags parameter has the same definition as the ulIntFlags parameter to TimerIntEnable().

Returns

None.

void TimerIntEnable	(	unsigned long	ulBase,
		unsigned long	ulIntFlags
	)

Enables individual timer interrupt sources.

Parameters

ulBase	is the base address of the timer module.
ulIntFlags	is the bit mask of the interrupt sources to be enabled.

Enables the indicated timer interrupt sources. Only the sources that are enabled can be reflected to the processor interrupt; disabled sources have no effect on the processor.

The ulIntFlags parameter must be the logical OR of any combination of the following:

• TIMER_CAPB_EVENT - Capture B event interrupt
• TIMER_CAPB_MATCH - Capture B match interrupt
• TIMER_TIMB_TIMEOUT - Timer B timeout interrupt
• TIMER_CAPA_EVENT - Capture A event interrupt
• TIMER_CAPA_MATCH - Capture A match interrupt
• TIMER_TIMA_TIMEOUT - Timer A timeout interrupt

Returns

None.

void TimerIntRegister	(	unsigned long	ulBase,
		unsigned long	ulTimer,
		void(*)(void)	pfnHandler
	)

Registers an interrupt handler for the timer interrupt.

Parameters

ulBase	is the base address of the timer module.
ulTimer	specifies the timer(s); must be one of TIMER_A, TIMER_B, or TIMER_BOTH.
pfnHandler	is a pointer to the function to be called when the timer interrupt occurs.

This function sets the handler to be called when a timer interrupt occurs. In addition, this function enables the global interrupt in the interrupt controller; specific timer interrupts must be enabled via TimerIntEnable(). It is the interrupt handler's responsibility to clear the interrupt source via TimerIntClear().

See also

IntRegister() for important information about registering interrupt handlers.

Returns

None.

unsigned long TimerIntStatus	(	unsigned long	ulBase,
		tBoolean	bMasked
	)

Gets the current interrupt status.

Parameters

ulBase	is the base address of the timer module.
bMasked	is false if the raw interrupt status is required and true if the masked interrupt status is required.

This function returns the interrupt status for the timer module. Either the raw interrupt status or the status of interrupts that are allowed to reflect to the processor can be returned.

Returns

The current interrupt status, enumerated as a bit field of values described in TimerIntEnable().

void TimerIntUnregister	(	unsigned long	ulBase,
		unsigned long	ulTimer
	)

Unregisters an interrupt handler for the timer interrupt.

Parameters

ulBase	is the base address of the timer module.
ulTimer	specifies the timer(s); must be one of TIMER_A, TIMER_B, or TIMER_BOTH.

This function clears the handler to be called when a timer interrupt occurs. This function also masks off the interrupt in the interrupt controller so that the interrupt handler no longer is called.

See also

IntRegister() for important information about registering interrupt handlers.

Returns

None.

unsigned long TimerLoadGet	(	unsigned long	ulBase,
		unsigned long	ulTimer
	)

Gets the timer load value.

Parameters

ulBase	is the base address of the timer module.
ulTimer	specifies the timer; must be one of TIMER_A or TIMER_B. Only TIMER_A should be used when the timer is configured for full-width operation.

This function gets the currently programmed interval load value for the specified timer.

Note

This function can be used for both full- and half-width modes of 16/32-bit timers.

Returns

Returns the load value for the timer.

void TimerLoadSet	(	unsigned long	ulBase,
		unsigned long	ulTimer,
		unsigned long	ulValue
	)

Sets the timer load value.

Parameters

ulBase	is the base address of the timer module.
ulTimer	specifies the timer(s) to adjust; must be one of TIMER_A, TIMER_B, or TIMER_BOTH. Only TIMER_A should be used when the timer is configured for full-width operation.
ulValue	is the load value.

This function sets the timer load value; if the timer is running then the value is immediately loaded into the timer.

Note

This function can be used for both full- and half-width modes of 16/32-bit timers.

Returns

None.

unsigned long TimerMatchGet	(	unsigned long	ulBase,
		unsigned long	ulTimer
	)

Gets the timer match value.

Parameters

ulBase	is the base address of the timer module.
ulTimer	specifies the timer; must be one of TIMER_A or TIMER_B. Only TIMER_A should be used when the timer is configured for 32-bit operation.

This function gets the match value for the specified timer.

Returns

Returns the match value for the timer.

void TimerMatchSet	(	unsigned long	ulBase,
		unsigned long	ulTimer,
		unsigned long	ulValue
	)

Sets the timer match value.

Parameters

ulBase	is the base address of the timer module.
ulTimer	specifies the timer(s) to adjust; must be one of TIMER_A, TIMER_B, or TIMER_BOTH. Only TIMER_A should be used when the timer is configured for 32-bit operation.
ulValue	is the match value.

This function sets the match value for a timer. This is used in capture count mode to determine when to interrupt the processor and in PWM mode to determine the duty cycle of the output signal.

Returns

None.

unsigned long TimerPrescaleGet	(	unsigned long	ulBase,
		unsigned long	ulTimer
	)

Get the timer prescale value.

Parameters

ulBase	is the base address of the timer module.
ulTimer	specifies the timer; must be one of TIMER_A or TIMER_B.

This function gets the value of the input clock prescaler. The prescaler is only operational when in half-width mode and is used to extend the range of the half-width timer modes.

Returns

The value of the timer prescaler.

unsigned long TimerPrescaleMatchGet	(	unsigned long	ulBase,
		unsigned long	ulTimer
	)

Get the timer prescale match value.

Parameters

ulBase	is the base address of the timer module.
ulTimer	specifies the timer; must be one of TIMER_A or TIMER_B.

This function gets the value of the input clock prescaler match value. When in a half-width mode that uses the counter match and prescaler, the prescale match effectively extends the range of the match.

Note

The availability of the prescaler match varies with the part and timer mode in use. Please consult the datasheet for the part you are using to determine whether this support is available.

Returns

The value of the timer prescale match.

void TimerPrescaleMatchSet	(	unsigned long	ulBase,
		unsigned long	ulTimer,
		unsigned long	ulValue
	)

Set the timer prescale match value.

Parameters

ulBase	is the base address of the timer module.
ulTimer	specifies the timer(s) to adjust; must be one of TIMER_A, TIMER_B, or TIMER_BOTH.
ulValue	is the timer prescale match value which must be between 0 and 255 (inclusive) for 16/32-bit timers.

This function sets the value of the input clock prescaler match value. When in a half-width mode that uses the counter match and the prescaler, the prescale match effectively extends the range of the match.

Note

The availability of the prescaler match varies with the part and timer mode in use. Please consult the datasheet for the part you are using to determine whether this support is available.

Returns

None.

void TimerPrescaleSet	(	unsigned long	ulBase,
		unsigned long	ulTimer,
		unsigned long	ulValue
	)

Set the timer prescale value.

Parameters

ulBase	is the base address of the timer module.
ulTimer	specifies the timer(s) to adjust; must be one of TIMER_A, TIMER_B, or TIMER_BOTH.
ulValue	is the timer prescale value which must be between 0 and 255 (inclusive) for 16/32-bit timers.

This function sets the value of the input clock prescaler. The prescaler is only operational when in half-width mode and is used to extend the range of the half-width timer modes.

Returns

None.

unsigned long TimerValueGet	(	unsigned long	ulBase,
		unsigned long	ulTimer
	)

Gets the current timer value.

Parameters

ulBase	is the base address of the timer module.
ulTimer	specifies the timer; must be one of TIMER_A or TIMER_B. Only TIMER_A should be used when the timer is configured for 32-bit operation.

This function reads the current value of the specified timer.

Returns

Returns the current value of the timer.

void TimerValueSet	(	unsigned long	ulBase,
		unsigned long	ulTimer,
		unsigned long	ulValue
	)

Sets the current timer value.

Parameters

ulBase	is the base address of the timer module.
ulTimer	specifies the timer; must be one of TIMER_A or TIMER_B. Only TIMER_A should be used when the timer is configured for 32-bit operation.
ulValue	is the new value of the timer to be set.

This function sets the current value of the specified timer.

Returns

None.