Overview

This section describes the programming interface of the CMT HAL driver.

Enumerations
enum	cmt_status_t
	Error codes for the CMT driver.

enum	cmt_mode_t { kCMTDirectIROCtl = 0x00U, kCMTTimeMode = 0x01U, kCMTFSKMode = 0x05U, kCMTBasebandMode = 0x09U }
	The modes of CMT. More...

enum	cmt_int_t { kCMTModeBitMask = 0x0DU, kCMTModulCountMask = 0xFFFF }
	The CMT macro definition for a specific value. More...

enum	cmt_primary_clkdiv_t { kCMTPriClkDiv1 = 0U, kCMTPriClkDiv2 = 1U, kCMTPriClkDiv3 = 2U, kCMTPriClkDiv4 = 3U, kCMTPriClkDiv5 = 4U, kCMTPriClkDiv6 = 5U, kCMTPriClkDiv7 = 6U, kCMTPriClkDiv8 = 7U, kCMTPriClkDiv9 = 8U, kCMTPriClkDiv10 = 9U, kCMTPriClkDiv11 = 10U, kCMTPriClkDiv12 = 11U, kCMTPriClkDiv13 = 12U, kCMTPriClkDiv14 = 13U, kCMTPriClkDiv15 = 14U, kCMTPriClkDiv16 = 15U }
	The CMT clock divide primary prescaler. More...

enum	cmt_second_clkdiv_t { kCMTSecClkDiv1 = 0U, kCMTSecClkDiv2 = 1U, kCMTSecClkDiv4 = 2U, kCMTSecClkDiv8 = 3U }
	The CMT clock divide secondary prescaler. More...

enum	cmt_iro_polarity_t { kCMTIROActiveLow = 0U, kCMTIROActiveHigh = 1U }
	The CMT output polarity. More...

enum	cmt_iro_ctl_t { kCMTIROCtlLow = 0U, kCMTIROCtlHigh = 1U }
	The CMT IRO latch control. More...

Initialization
void	CMT_HAL_Init (CMT_Type *base)
	Initializes the CMT module. More...

static void	CMT_HAL_SetMode (CMT_Type *base, cmt_mode_t mode)
	Selects the mode for CMT. More...

cmt_mode_t	CMT_HAL_GetMode (CMT_Type *base)
	Gets the mode of the CMT module. More...

static void	CMT_HAL_EnableExtendSpace (CMT_Type *base)
	Enables the extended space operation for the CMT modulator. More...

static void	CMT_HAL_DisableExtendSpace (CMT_Type *base)
	Disables the extended space operation for the CMT modulator. More...

static bool	CMT_HAL_IsExtendSpace (CMT_Type *base)
	Finds out whether the extended space feature is enabled. More...

Counters
static void	CMT_HAL_SetCGCountOne (CMT_Type *base, uint32_t highCount, uint32_t lowCount)
	Sets the primary data set for the CMT carrier generator counter. More...

static void	CMT_HAL_SetCGCountTwo (CMT_Type *base, uint32_t highCount, uint32_t lowCount)
	Sets the secondary data set for the CMT carrier generator counter. More...

static void	CMT_HAL_SetModulateMarkCount (CMT_Type *base, uint32_t markCount)
	Sets the modulation mark time period for the CMT modulator counter. More...

static void	CMT_HAL_SetModulateSpaceCount (CMT_Type *base, uint32_t spaceCount)
	Sets the modulation space time period for the CMT modulator counter. More...

Clock divider
static void	CMT_HAL_SetClkByDiv (CMT_Type *base, cmt_primary_clkdiv_t ppsDiv, cmt_second_clkdiv_t spsDiv)
	Configures the CMT clock by setting the clock divider. More...

static cmt_primary_clkdiv_t	CMT_HAL_GetPriClkDiv (CMT_Type *base)
	Gets the CMT primary clock divider. More...

static cmt_second_clkdiv_t	CMT_HAL_GetSecClkDiv (CMT_Type *base)
	Gets the CMT secondary clock divider. More...

Interrupt and DMA
static void	CMT_HAL_SetIntCmd (CMT_Type *base, bool enable)
	Enables or disables the CMT end of cycle interrupt. More...

static bool	CMT_HAL_GetIntCmd (CMT_Type *base)
	Gets whether the CMT end of cycle interrupt is enabled or not. More...

static bool	CMT_HAL_IsEndofCycle (CMT_Type *base)
	Reads the end of cycle status flag. More...

static void	CMT_HAL_SetDMACmd (CMT_Type *base, bool enable)
	Enables or disables the DMA. More...

static bool	CMT_HAL_GetDMACmd (CMT_Type *base)
	Gets whether the DMA is enabled or not. More...

Output signal Control
static void	CMT_HAL_SetIroPol (CMT_Type *base, cmt_iro_polarity_t polarVal)
	Controls the CMT output signal polarity. More...

static void	CMT_HAL_SetIroCmd (CMT_Type *base, bool enable)
	Enables or disables the IRO signal. More...

static void	CMT_HAL_SetIroCtl (CMT_Type *base, cmt_iro_ctl_t ctlVal)
	Controls the IRO latch. More...

static bool	CMT_HAL_GetIrolatchState (CMT_Type *base)
	Reads the states of the IRO latch. More...

Enumeration Type Documentation

enum cmt_mode_t

Enumerator
kCMTDirectIROCtl	Carrier modulator is disabled and the IRO signal is directly in software control.
kCMTTimeMode	Carrier modulator is enabled in time mode.
kCMTFSKMode	Carrier modulator is enabled in FSK mode.
kCMTBasebandMode	Carrier modulator is enabled in baseband mode.

enum cmt_int_t

Enumerator
kCMTModeBitMask	CMT mode bit mask.
kCMTModulCountMask	CMT modulator count mask.

enum cmt_primary_clkdiv_t

Enumerator
kCMTPriClkDiv1	The intermediate frequency is the bus clock divided by 1.
kCMTPriClkDiv2	The intermediate frequency is the bus clock divided by 2.
kCMTPriClkDiv3	The intermediate frequency is the bus clock divided by 3.
kCMTPriClkDiv4	The intermediate frequency is the bus clock divided by 4.
kCMTPriClkDiv5	The intermediate frequency is the bus clock divided by 5.
kCMTPriClkDiv6	The intermediate frequency is the bus clock divided by 6.
kCMTPriClkDiv7	The intermediate frequency is the bus clock divided by 7.
kCMTPriClkDiv8	The intermediate frequency is the bus clock divided by 8.
kCMTPriClkDiv9	The intermediate frequency is the bus clock divided by 9.
kCMTPriClkDiv10	The intermediate frequency is the bus clock divided by 10.
kCMTPriClkDiv11	The intermediate frequency is the bus clock divided by 11.
kCMTPriClkDiv12	The intermediate frequency is the bus clock divided by 12.
kCMTPriClkDiv13	The intermediate frequency is the bus clock divided by 13.
kCMTPriClkDiv14	The intermediate frequency is the bus clock divided by 14.
kCMTPriClkDiv15	The intermediate frequency is the bus clock divided by 15.
kCMTPriClkDiv16	The intermediate frequency is the bus clock divided by 16.

enum cmt_second_clkdiv_t

Enumerator
kCMTSecClkDiv1	The CMT clock is the intermediate frequency frequency divided by 1.
kCMTSecClkDiv2	The CMT clock is the intermediate frequency frequency divided by 2.
kCMTSecClkDiv4	The CMT clock is the intermediate frequency frequency divided by 4.
kCMTSecClkDiv8	The CMT clock is the intermediate frequency frequency divided by 8.

enum cmt_iro_polarity_t

Enumerator
kCMTIROActiveLow	The CMT IRO signal is active-low.
kCMTIROActiveHigh	The CMT IRO signal is active-high.

enum cmt_iro_ctl_t

Enumerator
kCMTIROCtlLow	The CMT IRO signal is controlled to low.
kCMTIROCtlHigh	The CMT IRO signal is controlled to high.

Function Documentation

void CMT_HAL_Init ( CMT_Type * base )

This function initializes the CMT module. All control and data settings are cleared after initialization.

Parameters

base	Base address for current CMT instance.

static void CMT_HAL_SetMode	(	CMT_Type *	base,
		cmt_mode_t	mode
	)

inlinestatic

This function selects the mode for CMT. The function is called during CMT initialization.

Parameters

base	Base address for current CMT instance.
mode	Selection of CMT feature mode enumeration. See to "cmt_mode_t".

cmt_mode_t CMT_HAL_GetMode ( CMT_Type * base )

This function gets the mode of the CMT module .

Parameters

base	Base address for current CMT instance.

Returns: The mode of CMT module, See to "cmt_mode_t".

static void CMT_HAL_EnableExtendSpace ( CMT_Type * base )

inlinestatic

This function enables the extended space operation for the CMT modulator. It enlarges the space period for CMT and causes subsequent modulator cycles to be spaces for the duration of the modulator. It should be used in the CMT time, baseband, or FSK mode. This means it's valid when the CMT carrier generator and modulator is enabled.

Parameters

base	Base address for current CMT instance.

static void CMT_HAL_DisableExtendSpace ( CMT_Type * base )

inlinestatic

This function disables the extended space operation for the CMT modulator. It can be used to return the modulator to a standard operation when the extended space operation has been enabled.

Parameters

base	Base address for current CMT instance.

static bool CMT_HAL_IsExtendSpace ( CMT_Type * base )

inlinestatic

This function finds out whether the extended space is enabled for the CMT modulator. When the carrier generator and modulator is enabled, this function can be used to check whether the extended space feature is opened or not.

Parameters

base	Base address for the current CMT instance.

Returns

Current status of the extended space feature.

true: the extended space feature is enabled.
false: the extended space feature is disabled.

static void CMT_HAL_SetCGCountOne	(	CMT_Type *	base,
		uint32_t	highCount,
		uint32_t	lowCount
	)

inlinestatic

This function sets the high time and low time of the primary data set for the CMT carrier generator counter to control the period and the duty cycle of the output carrier signal. If the CMT clock period is Tcmt, The period of the carrier generator signal equals (highCount + lowCount) * Tcmt. The duty cycle equals highCount / (highCount + lowCount).

Parameters

base	Base address for current CMT instance.
highCount	The number of CMT clocks for carrier generator signal high time, integer in the range of 0 ~ 0xFF.
lowCount	The number of CMT clocks for carrier generator signal low time, integer in the range of 0 ~ 0xFF.

static void CMT_HAL_SetCGCountTwo	(	CMT_Type *	base,
		uint32_t	highCount,
		uint32_t	lowCount
	)

inlinestatic

This function sets the high time and low time of the secondary data set CMT carrier generator counter to control the period and the duty cycle of the output carrier signal. If the CMT clock period is Tcmt, The period of the carrier generator signal equals (highCount + lowCount) * Tcmt. The duty cycle equals highCount / (highCount + lowCount). This data set is mainly used for FSK mode.

Parameters

base	Base address for current CMT instance.
highCount	The number of CMT clocks for carrier generator signal high time, integer in the range of 0 ~ 0xFF.
lowCount	The number of CMT clocks for carrier generator signal low time, integer in the range of 0 ~ 0xFF.

static void CMT_HAL_SetModulateMarkCount	(	CMT_Type *	base,
		uint32_t	markCount
	)

inlinestatic

This function sets the mark time period of the CMT modulator counter to control the mark time of the output modulated signal from the carrier generator output signal. If the CMT clock frequency is Fcmt and the carrier out signal frequency is fcg:

In Time and Baseband mode: The mark period of the generated signal equals (markCount + 1) / (Fcmt/8).
In FSK mode:The mark period of the generated signal equals (markCount + 1)/fcg.

Parameters

base	Base address for current CMT instance.
markCount	The number of clock period for CMT modulator signal mark period, in the range of 0 ~ 0xFFFF.

static void CMT_HAL_SetModulateSpaceCount	(	CMT_Type *	base,
		uint32_t	spaceCount
	)

inlinestatic

This function sets the mark time period of the CMT modulator counter to control the space time of the output modulated signal from the carrier generator output signal. If the CMT clock frequency is Fcmt and the carrier out signal frequency is fcg:

In Time and Baseband mode: The space period of the generated signal equals spaceCount / (Fcmt/8).
In FSK mode:The space period of the generated signal equals spaceCount/fcg.

Parameters

base	Base address for current CMT instance.
spaceCount	The number of clock period for CMT modulator signal space period, in the range of 0 ~ 0xFFFF.

static void CMT_HAL_SetClkByDiv	(	CMT_Type *	base,
		cmt_primary_clkdiv_t	ppsDiv,
		cmt_second_clkdiv_t	spsDiv
	)

inlinestatic

There are two prescalers with 8 MHz or higher frequency in the clock divider block for the CMT flexible clock frequency generation from the bus clock.

Parameters

base	Base address for current CMT instance.
ppsDiv	The primary prescaler divider. ppsDiv should be a integer range between 0 ~ 15 representing the divisor 1 ~ 16 (See "cmt_primary_clkdiv_t"). It divides the bus clock to generate the Intermediate Frequency clock. The Intermediate frequency (IF) clock should be approximately 8 MHz. For example, if the bus clock is 50 MHz, ppsDiv should be set to kCMTPriClkDivSix, then IF = 50 MHz/6 = 8.333.333... . if the bus clock is 8 MHz, ppsDiv should be set to kCMTPriClkDivOne.
spsDiv	The secondary prescaler divider. The CMT carrier generator resolution is 8Mhz/(2 ^ spsDiv) . spsDiv should be a integer range between 0 ~ 3 representing the divisor 1,2,4 and 8 (See "cmt_second_clkdiv_t").

static cmt_primary_clkdiv_t CMT_HAL_GetPriClkDiv ( CMT_Type * base )

inlinestatic

Parameters

base	Base address for current CMT instance.

Returns: The CMT primary clock divider.

static cmt_second_clkdiv_t CMT_HAL_GetSecClkDiv ( CMT_Type * base )

inlinestatic

Parameters

base	Base address for current CMT instance.

Returns: The CMT secondary clock divider.

static void CMT_HAL_SetIntCmd	(	CMT_Type *	base,
		bool	enable
	)

inlinestatic

If enabled, an interrupt occurs at the end of the modulator cycle or when the CMT_HAL_IsEndofCycle returns true. (Note: NVIC should be called to enable the CMT interrupt on the system level).

Parameters

base	Base address for current CMT instance.
enable	Enable or disable interrupt. true: CPU interrupt is enabled. false: CPU interrupt is disabled.

static bool CMT_HAL_GetIntCmd ( CMT_Type * base )

inlinestatic

Parameters

base	Base address for current CMT instance.

Returns

Status of enabled or disabled interrupt

true: Interrupt is enabled.
false: Interrupt is disabled.

static bool CMT_HAL_IsEndofCycle ( CMT_Type * base )

inlinestatic

The flag is set:

When the modulator is not currently active and carrier and modulator is set to start the initial CMT transmission.
At the end of each modulation cycle when the counter is reloaded and the carrier and modulator are enabled.
Parameters

base Base address for current CMT instance.

Returns
Current status of the end of cycle status flag

true: End-of-cycle has occurred.

false: End-of-cycle has not yet occurred since the flag last cleared.

static void CMT_HAL_SetDMACmd	(	CMT_Type *	base,
		bool	enable
	)

inlinestatic

If enabled, a DMA transfer request occurs at the end of the modulator cycle when the end-of-cycle interrupt is enabled.

Parameters

base	Base address for current CMT instance.
enable	Enable or disable DMA. true: DMA transfer request and done are enabled. false: DMA transfer request and done are disabled.

static bool CMT_HAL_GetDMACmd ( CMT_Type * base )

inlinestatic

Parameters

base	Base address for current CMT instance.

Returns

Status of enabled or disabled DMA

true: DMA is enabled.
false: DMA is disabled.

static void CMT_HAL_SetIroPol	(	CMT_Type *	base,
		cmt_iro_polarity_t	polarVal
	)

inlinestatic

Parameters

base	Base address for current CMT instance.
polarVal	The polarity of the IRO signal. See "cmt_iro_polarity_t"

static void CMT_HAL_SetIroCmd	(	CMT_Type *	base,
		bool	enable
	)

inlinestatic

This function enables and disables the IRO signal. When the IRO signal is enabled, it is an output that drives out either the CMT transmitter output or the state of IRO latch control depending on whether the carrier modulator is enabled.

Parameters

base	Base address for current CMT instance.
enable	Enable or disable IRO signal. true: The IRO signal is enabled. false: The IRO signal is disabled.

static void CMT_HAL_SetIroCtl	(	CMT_Type *	base,
		cmt_iro_ctl_t	ctlVal
	)

inlinestatic

This function changes the states of the IRO signal when the kCMTDirectIROMode mode is set and the IRO signal is enabled.

Parameters

base	Base address for current CMT instance.
ctlVal	The control of the IRO signal. See "cmt_iro_ctl_t"

static bool CMT_HAL_GetIrolatchState ( CMT_Type * base )

inlinestatic

Parameters

base	Base address for current CMT instance.

Returns: The states of the IRO latch

Overview

Enumerations

Initialization

Counters

Clock divider

Interrupt and DMA

Output signal Control

Enumeration Type Documentation

Function Documentation