Detailed Description

Low Energy Universal Asynchronous Receiver/Transmitter (LEUART) Peripheral API.

This module contains functions to control the LEUART peripheral of Silicon Labs 32-bit MCUs and SoCs. The LEUART provides full UART communication using a low frequency 32.768 kHz clock, and has special features for communication without CPU intervention.

Data Structures
struct	LEUART_Init_TypeDef

Macros
#define	LEUART_INIT_DEFAULT

Enumerations
enum	LEUART_Databits_TypeDef { leuartDatabits8 = LEUART_CTRL_DATABITS_EIGHT, leuartDatabits9 = LEUART_CTRL_DATABITS_NINE }

enum	LEUART_Enable_TypeDef { leuartDisable = 0x0, leuartEnableRx = LEUART_CMD_RXEN, leuartEnableTx = LEUART_CMD_TXEN, leuartEnable = (LEUART_CMD_RXEN \| LEUART_CMD_TXEN) }

enum	LEUART_Parity_TypeDef { leuartNoParity = LEUART_CTRL_PARITY_NONE, leuartEvenParity = LEUART_CTRL_PARITY_EVEN, leuartOddParity = LEUART_CTRL_PARITY_ODD }

enum	LEUART_Stopbits_TypeDef { leuartStopbits1 = LEUART_CTRL_STOPBITS_ONE, leuartStopbits2 = LEUART_CTRL_STOPBITS_TWO }

Functions
uint32_t	LEUART_BaudrateCalc (uint32_t refFreq, uint32_t clkdiv)
	Calculate baudrate for LEUART given reference frequency and clock division. More...

uint32_t	LEUART_BaudrateGet (LEUART_TypeDef *leuart)
	Get current baudrate for LEUART. More...

void	LEUART_BaudrateSet (LEUART_TypeDef *leuart, uint32_t refFreq, uint32_t baudrate)
	Configure baudrate (or as close as possible to specified baudrate). More...

void	LEUART_Enable (LEUART_TypeDef *leuart, LEUART_Enable_TypeDef enable)
	Enable/disable LEUART receiver and/or transmitter. More...

void	LEUART_FreezeEnable (LEUART_TypeDef *leuart, bool enable)
	LEUART register synchronization freeze control. More...

void	LEUART_Init (LEUART_TypeDef leuart, LEUART_Init_TypeDef const init)
	Init LEUART. More...

__STATIC_INLINE void	LEUART_IntClear (LEUART_TypeDef *leuart, uint32_t flags)
	Clear one or more pending LEUART interrupts. More...

__STATIC_INLINE void	LEUART_IntDisable (LEUART_TypeDef *leuart, uint32_t flags)
	Disable one or more LEUART interrupts. More...

__STATIC_INLINE void	LEUART_IntEnable (LEUART_TypeDef *leuart, uint32_t flags)
	Enable one or more LEUART interrupts. More...

__STATIC_INLINE uint32_t	LEUART_IntGet (LEUART_TypeDef *leuart)
	Get pending LEUART interrupt flags. More...

__STATIC_INLINE uint32_t	LEUART_IntGetEnabled (LEUART_TypeDef *leuart)
	Get enabled and pending LEUART interrupt flags. Useful for handling more interrupt sources in the same interrupt handler. More...

__STATIC_INLINE void	LEUART_IntSet (LEUART_TypeDef *leuart, uint32_t flags)
	Set one or more pending LEUART interrupts from SW. More...

void	LEUART_Reset (LEUART_TypeDef *leuart)
	Reset LEUART to same state as after a HW reset. More...

uint8_t	LEUART_Rx (LEUART_TypeDef *leuart)
	Receive one 8 bit frame, (or part of 9 bit frame). More...

__STATIC_INLINE uint8_t	LEUART_RxDataGet (LEUART_TypeDef *leuart)
	Receive one 8 bit frame, (or part of a 9 bit frame). More...

__STATIC_INLINE uint16_t	LEUART_RxDataXGet (LEUART_TypeDef *leuart)
	Receive one 8-9 bit frame, with extended information. More...

void	LEUART_RxDmaInEM2Enable (LEUART_TypeDef *leuart, bool enable)
	Enables handling of LEUART RX by DMA in EM2. More...

uint16_t	LEUART_RxExt (LEUART_TypeDef *leuart)
	Receive one 8-9 bit frame, with extended information. More...

__STATIC_INLINE uint32_t	LEUART_StatusGet (LEUART_TypeDef *leuart)
	Get LEUART STATUS register. More...

void	LEUART_Tx (LEUART_TypeDef *leuart, uint8_t data)
	Transmit one frame. More...

void	LEUART_TxDmaInEM2Enable (LEUART_TypeDef *leuart, bool enable)
	Enables handling of LEUART TX by DMA in EM2. More...

void	LEUART_TxExt (LEUART_TypeDef *leuart, uint16_t data)
	Transmit one 8-9 bit frame with extended control. More...

Macro Definition Documentation

#define LEUART_INIT_DEFAULT

Value:

{                                                                                           \
  leuartEnable,      /* Enable RX/TX when init completed. */                                \
  0,                 /* Use current configured reference clock for configuring baudrate. */ \
  9600,              /* 9600 bits/s. */                                                     \
  leuartDatabits8,   /* 8 databits. */                                                      \
  leuartNoParity,    /* No parity. */                                                       \
  leuartStopbits1    /* 1 stopbit. */                                                       \
}

Default config for LEUART init structure.

Definition at line 132 of file em_leuart.h.

Referenced by BSP_BccInit(), RETARGET_SerialInit(), and UARTDRV_InitLeuart().

Enumeration Type Documentation

enum LEUART_Databits_TypeDef

Databit selection.

Enumerator
leuartDatabits8	8 databits.
leuartDatabits9	9 databits.

Definition at line 61 of file em_leuart.h.

enum LEUART_Enable_TypeDef

Enable selection.

Enumerator
leuartDisable	Disable both receiver and transmitter.
leuartEnableRx	Enable receiver only, transmitter disabled.
leuartEnableTx	Enable transmitter only, receiver disabled.
leuartEnable	Enable both receiver and transmitter.

Definition at line 69 of file em_leuart.h.

enum LEUART_Parity_TypeDef

Parity selection.

Enumerator
leuartNoParity	No parity.
leuartEvenParity	Even parity.
leuartOddParity	Odd parity.

Definition at line 86 of file em_leuart.h.

enum LEUART_Stopbits_TypeDef

Stopbits selection.

Enumerator
leuartStopbits1	1 stopbits.
leuartStopbits2	2 stopbits.

Definition at line 95 of file em_leuart.h.

Function Documentation

uint32_t LEUART_BaudrateCalc	(	uint32_t	refFreq,
		uint32_t	clkdiv
	)

Calculate baudrate for LEUART given reference frequency and clock division.

This function returns the baudrate that a LEUART module will use if configured with the given frequency and clock divisor. Notice that this function will not use actual HW configuration. It can be used to determinate if a given configuration is sufficiently accurate for the application.

Parameters

[in]	refFreq	LEUART peripheral frequency used.
[in]	clkdiv	Clock division factor to be used.

Returns: Baudrate with given settings.

Definition at line 134 of file em_leuart.c.

References _LEUART_CLKDIV_MASK.

Referenced by LEUART_BaudrateGet().

uint32_t LEUART_BaudrateGet ( LEUART_TypeDef * leuart )

Get current baudrate for LEUART.

This function returns the actual baudrate (not considering oscillator inaccuracies) used by a LEUART peripheral.

Parameters

[in] leuart Pointer to LEUART peripheral register block.

Returns: Current baudrate.

Definition at line 212 of file em_leuart.c.

References LEUART_TypeDef::CLKDIV, CMU_ClockFreqGet(), cmuClock_LEUART0, cmuClock_LEUART1, LEUART0, LEUART1, and LEUART_BaudrateCalc().

void LEUART_BaudrateSet	(	LEUART_TypeDef *	leuart,
		uint32_t	refFreq,
		uint32_t	baudrate
	)

Configure baudrate (or as close as possible to specified baudrate).

Note: The setting of a baudrate requires synchronization into the low frequency domain. If the same register is modified before a previous update has completed, this function will stall until the previous synchronization has completed.

Parameters

[in]	leuart	Pointer to LEUART peripheral register block.
[in]	refFreq	LEUART reference clock frequency in Hz that will be used. If set to 0, the currently configured reference clock is assumed.
[in]	baudrate	Baudrate to try to achieve for LEUART.

Definition at line 260 of file em_leuart.c.

References _LEUART_CLKDIV_MASK, LEUART_TypeDef::CLKDIV, CMU_ClockFreqGet(), cmuClock_LEUART0, cmuClock_LEUART1, LEUART0, LEUART1, and LEUART_SYNCBUSY_CLKDIV.

Referenced by LEUART_Init().

void LEUART_Enable	(	LEUART_TypeDef *	leuart,
		LEUART_Enable_TypeDef	enable
	)

Enable/disable LEUART receiver and/or transmitter.

Notice that this function does not do any configuration. Enabling should normally be done after initialization is done (if not enabled as part of init).

Note: Enabling/disabling requires synchronization into the low frequency domain. If the same register is modified before a previous update has completed, this function will stall until the previous synchronization has completed.

Parameters

[in]	leuart	Pointer to LEUART peripheral register block.
[in]	enable	Select status for receiver/transmitter.

Definition at line 357 of file em_leuart.c.

References _LEUART_CMD_RXEN_MASK, _LEUART_CMD_TXEN_MASK, LEUART_TypeDef::CMD, and LEUART_SYNCBUSY_CMD.

Referenced by RETARGET_SerialInit(), and UARTDRV_InitLeuart().

void LEUART_FreezeEnable	(	LEUART_TypeDef *	leuart,
		bool	enable
	)

LEUART register synchronization freeze control.

Some LEUART registers require synchronization into the low frequency (LF) domain. The freeze feature allows for several such registers to be modified before passing them to the LF domain simultaneously (which takes place when the freeze mode is disabled).

Note: When enabling freeze mode, this function will wait for all current ongoing LEUART synchronization to LF domain to complete (Normally synchronization will not be in progress.) However for this reason, when using freeze mode, modifications of registers requiring LF synchronization should be done within one freeze enable/disable block to avoid unecessary stalling.

Parameters

[in]	leuart	Pointer to LEUART peripheral register block.
[in]	enable	true - enable freeze, modified registers are not propagated to the LF domain false - disables freeze, modified registers are propagated to LF domain

Definition at line 405 of file em_leuart.c.

References LEUART_TypeDef::FREEZE, LEUART_FREEZE_REGFREEZE, and LEUART_TypeDef::SYNCBUSY.

Referenced by LEUART_Init(), and LEUART_Reset().

void LEUART_Init	(	LEUART_TypeDef *	leuart,
		LEUART_Init_TypeDef const *	init
	)

Init LEUART.

This function will configure basic settings in order to operate in normal asynchronous mode. Consider using LEUART_Reset() prior to this function if state of configuration is not known, since only configuration settings specified by init are set.

Special control setup not covered by this function may be done either before or after using this function (but normally before enabling) by direct modification of the CTRL register.

Notice that pins used by the LEUART module must be properly configured by the user explicitly, in order for the LEUART to work as intended. (When configuring pins, one should remember to consider the sequence of configuration, in order to avoid unintended pulses/glitches on output pins.)

Note: Initializing requires synchronization into the low frequency domain. If the same register is modified before a previous update has completed, this function will stall until the previous synchronization has completed.

Parameters

[in]	leuart	Pointer to LEUART peripheral register block.
[in]	init	Pointer to initialization structure used to configure basic async setup.

Definition at line 461 of file em_leuart.c.

References _LEUART_CTRL_PARITY_MASK, _LEUART_CTRL_STOPBITS_MASK, LEUART_Init_TypeDef::baudrate, LEUART_TypeDef::CMD, LEUART_TypeDef::CTRL, LEUART_Init_TypeDef::databits, LEUART_Init_TypeDef::enable, LEUART_BaudrateSet(), LEUART_CMD_RXDIS, LEUART_CMD_TXDIS, LEUART_FreezeEnable(), LEUART_SYNCBUSY_CMD, LEUART_Init_TypeDef::parity, LEUART_Init_TypeDef::refFreq, and LEUART_Init_TypeDef::stopbits.

Referenced by BSP_BccInit(), RETARGET_SerialInit(), and UARTDRV_InitLeuart().

__STATIC_INLINE void LEUART_IntClear	(	LEUART_TypeDef *	leuart,
		uint32_t	flags
	)

Clear one or more pending LEUART interrupts.

Parameters

[in]	leuart	Pointer to LEUART peripheral register block.
[in]	flags	Pending LEUART interrupt source to clear. Use a bitwise logic OR combination of valid interrupt flags for the LEUART module (LEUART_IF_nnn).

Definition at line 169 of file em_leuart.h.

References LEUART_TypeDef::IFC.

Referenced by RETARGET_SerialInit(), and UARTDRV_InitLeuart().

__STATIC_INLINE void LEUART_IntDisable	(	LEUART_TypeDef *	leuart,
		uint32_t	flags
	)

Disable one or more LEUART interrupts.

Parameters

[in]	leuart	Pointer to LEUART peripheral register block.
[in]	flags	LEUART interrupt sources to disable. Use a bitwise logic OR combination of valid interrupt flags for the LEUART module (LEUART_IF_nnn).

Definition at line 186 of file em_leuart.h.

References LEUART_TypeDef::IEN.

__STATIC_INLINE void LEUART_IntEnable	(	LEUART_TypeDef *	leuart,
		uint32_t	flags
	)

Enable one or more LEUART interrupts.

Note: Depending on the use, a pending interrupt may already be set prior to enabling the interrupt. Consider using LEUART_IntClear() prior to enabling if such a pending interrupt should be ignored.

Parameters

[in]	leuart	Pointer to LEUART peripheral register block.
[in]	flags	LEUART interrupt sources to enable. Use a bitwise logic OR combination of valid interrupt flags for the LEUART module (LEUART_IF_nnn).

Definition at line 208 of file em_leuart.h.

References LEUART_TypeDef::IEN.

Referenced by RETARGET_SerialInit().

__STATIC_INLINE uint32_t LEUART_IntGet ( LEUART_TypeDef * leuart )

Get pending LEUART interrupt flags.

Note: The event bits are not cleared by the use of this function.

Parameters

[in] leuart Pointer to LEUART peripheral register block.

Returns: LEUART interrupt sources pending. A bitwise logic OR combination of valid interrupt flags for the LEUART module (LEUART_IF_nnn).

Definition at line 228 of file em_leuart.h.

References LEUART_TypeDef::IF.

__STATIC_INLINE uint32_t LEUART_IntGetEnabled ( LEUART_TypeDef * leuart )

Get enabled and pending LEUART interrupt flags. Useful for handling more interrupt sources in the same interrupt handler.

Parameters

[in] leuart Pointer to LEUART peripheral register block.

Note: Interrupt flags are not cleared by the use of this function.

Returns

Pending and enabled LEUART interrupt sources. The return value is the bitwise AND combination of

the OR combination of enabled interrupt sources in LEUARTx_IEN_nnn register (LEUARTx_IEN_nnn) and
the OR combination of valid interrupt flags of the LEUART module (LEUARTx_IF_nnn).

Definition at line 253 of file em_leuart.h.

References LEUART_TypeDef::IEN, and LEUART_TypeDef::IF.

__STATIC_INLINE void LEUART_IntSet	(	LEUART_TypeDef *	leuart,
		uint32_t	flags
	)

Set one or more pending LEUART interrupts from SW.

Parameters

[in]	leuart	Pointer to LEUART peripheral register block.
[in]	flags	LEUART interrupt sources to set to pending. Use a bitwise logic OR combination of valid interrupt flags for the LEUART module (LEUART_IF_nnn).

Definition at line 277 of file em_leuart.h.

References LEUART_TypeDef::IFS.

void LEUART_Reset ( LEUART_TypeDef * leuart )

Reset LEUART to same state as after a HW reset.

Parameters

[in] leuart Pointer to LEUART peripheral register block.

Definition at line 500 of file em_leuart.c.

References _LEUART_CLKDIV_RESETVALUE, _LEUART_CTRL_RESETVALUE, _LEUART_IEN_RESETVALUE, _LEUART_IFC_MASK, _LEUART_PULSECTRL_RESETVALUE, _LEUART_ROUTE_RESETVALUE, _LEUART_SIGFRAME_RESETVALUE, _LEUART_STARTFRAME_RESETVALUE, LEUART_TypeDef::CLKDIV, LEUART_TypeDef::CMD, LEUART_TypeDef::CTRL, LEUART_TypeDef::IEN, LEUART_TypeDef::IFC, LEUART_CMD_CLEARRX, LEUART_CMD_CLEARTX, LEUART_CMD_RXBLOCKDIS, LEUART_CMD_RXDIS, LEUART_CMD_TXDIS, LEUART_FreezeEnable(), LEUART_TypeDef::PULSECTRL, LEUART_TypeDef::ROUTE, LEUART_TypeDef::SIGFRAME, and LEUART_TypeDef::STARTFRAME.

Referenced by BSP_BccDeInit(), and UARTDRV_DeInit().

uint8_t LEUART_Rx ( LEUART_TypeDef * leuart )

Receive one 8 bit frame, (or part of 9 bit frame).

This function is normally used to receive one frame when operating with frame length 8 bits. Please refer to LEUART_RxExt() for reception of 9 bit frames.

Notice that possible parity/stop bits are not considered part of specified frame bit length.

Note: This function will stall if buffer is empty, until data is received.

Parameters

[in] leuart Pointer to LEUART peripheral register block.

Returns: Data received.

Definition at line 551 of file em_leuart.c.

References LEUART_STATUS_RXDATAV, LEUART_TypeDef::RXDATA, and LEUART_TypeDef::STATUS.

__STATIC_INLINE uint8_t LEUART_RxDataGet ( LEUART_TypeDef * leuart )

Receive one 8 bit frame, (or part of a 9 bit frame).

This function is used to quickly receive one 8 bit frame by reading the RXDATA register directly, without checking the STATUS register for the RXDATAV flag. This can be useful from the RXDATAV interrupt handler, i.e. waiting is superfluous, in order to quickly read the received data. Please refer to LEUART_RxDataXGet() for reception of 9 bit frames.

Note: Since this function does not check whether the RXDATA register actually holds valid data, it should only be used in situations when it is certain that there is valid data, ensured by some external program routine, e.g. like when handling an RXDATAV interrupt. The LEUART_Rx() is normally a better choice if the validity of the RXDATA register is not certain.; Notice that possible parity/stop bits are not considered part of specified frame bit length.

Parameters

[in] leuart Pointer to LEUART peripheral register block.

Returns: Data received.

Definition at line 334 of file em_leuart.h.

References LEUART_TypeDef::RXDATA.

__STATIC_INLINE uint16_t LEUART_RxDataXGet ( LEUART_TypeDef * leuart )

Receive one 8-9 bit frame, with extended information.

This function is used to quickly receive one 8-9 bit frame with extended information by reading the RXDATAX register directly, without checking the STATUS register for the RXDATAV flag. This can be useful from the RXDATAV interrupt handler, i.e. waiting is superfluous, in order to quickly read the received data.

Note: Since this function does not check whether the RXDATAX register actually holds valid data, it should only be used in situations when it is certain that there is valid data, ensured by some external program routine, e.g. like when handling an RXDATAV interrupt. The LEUART_RxExt() is normally a better choice if the validity of the RXDATAX register is not certain.; Notice that possible parity/stop bits are not considered part of specified frame bit length.

Parameters

[in] leuart Pointer to LEUART peripheral register block.

Returns: Data received.

Definition at line 368 of file em_leuart.h.

References LEUART_TypeDef::RXDATAX.

void LEUART_RxDmaInEM2Enable	(	LEUART_TypeDef *	leuart,
		bool	enable
	)

Enables handling of LEUART RX by DMA in EM2.

Parameters

[in]	leuart	Pointer to LEUART peripheral register block.
[in]	enable	true - enables functionality false - disables functionality

Definition at line 692 of file em_leuart.c.

References LEUART_TypeDef::CTRL, LEUART_CTRL_RXDMAWU, and LEUART_SYNCBUSY_CTRL.

uint16_t LEUART_RxExt ( LEUART_TypeDef * leuart )

Receive one 8-9 bit frame, with extended information.

This function is normally used to receive one frame and additional RX status information is required.

Note: This function will stall if buffer is empty, until data is received.

Parameters

[in] leuart Pointer to LEUART peripheral register block.

Returns: Data received.

Definition at line 577 of file em_leuart.c.

References LEUART_STATUS_RXDATAV, LEUART_TypeDef::RXDATAX, and LEUART_TypeDef::STATUS.

__STATIC_INLINE uint32_t LEUART_StatusGet ( LEUART_TypeDef * leuart )

Get LEUART STATUS register.

Parameters

[in] leuart Pointer to LEUART peripheral register block.

Returns: STATUS register value.

Definition at line 294 of file em_leuart.h.

References LEUART_TypeDef::STATUS.

void LEUART_Tx	(	LEUART_TypeDef *	leuart,
		uint8_t	data
	)

Transmit one frame.

Depending on frame length configuration, 8 (least significant) bits from data are transmitted. If frame length is 9, 8 bits are transmitted from data and one bit as specified by CTRL register, BIT8DV field. Please refer to LEUART_TxExt() for transmitting 9 bit frame with full control of all 9 bits.

Notice that possible parity/stop bits in asynchronous mode are not considered part of specified frame bit length.

Note: This function will stall if buffer is full, until buffer becomes available.

Parameters

[in]	leuart	Pointer to LEUART peripheral register block.
[in]	data	Data to transmit. See details above for further info.

Definition at line 609 of file em_leuart.c.

References LEUART_STATUS_TXBL, LEUART_SYNCBUSY_TXDATA, LEUART_TypeDef::STATUS, and LEUART_TypeDef::TXDATA.

Referenced by UARTDRV_ForceTransmit().

void LEUART_TxDmaInEM2Enable	(	LEUART_TypeDef *	leuart,
		bool	enable
	)

Enables handling of LEUART TX by DMA in EM2.

Parameters

[in]	leuart	Pointer to LEUART peripheral register block.
[in]	enable	true - enables functionality false - disables functionality

Definition at line 665 of file em_leuart.c.

References LEUART_TypeDef::CTRL, LEUART_CTRL_TXDMAWU, and LEUART_SYNCBUSY_CTRL.

void LEUART_TxExt	(	LEUART_TypeDef *	leuart,
		uint16_t	data
	)

Transmit one 8-9 bit frame with extended control.

Notice that possible parity/stop bits in asynchronous mode are not considered part of specified frame bit length.

Note: This function will stall if buffer is full, until buffer becomes available.

Parameters

[in]	leuart	Pointer to LEUART peripheral register block.
[in]	data	Data to transmit with extended control. Least significant bits contains frame bits, and additional control bits are available as documented in the reference manual (set to 0 if not used).

Definition at line 641 of file em_leuart.c.

References LEUART_STATUS_TXBL, LEUART_SYNCBUSY_TXDATAX, LEUART_TypeDef::STATUS, and LEUART_TypeDef::TXDATAX.

Detailed Description

Data Structures

Macros

Enumerations

Functions

Macro Definition Documentation

Enumeration Type Documentation

Function Documentation