LEUART - Low Energy UART#

LEUART_Databits_TypeDef#

LEUART_Databits_TypeDef

Data bit selection.

LEUART_Enable_TypeDef#

LEUART_Enable_TypeDef

Enable selection.

LEUART_Parity_TypeDef#

LEUART_Parity_TypeDef

Parity selection.

LEUART_Stopbits_TypeDef#

LEUART_Stopbits_TypeDef

Stop bits selection.

LEUART_BaudrateCalc#

uint32_t LEUART_BaudrateCalc (uint32_t refFreq, uint32_t clkdiv)

Calculate the baudrate for the 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 the hardware configuration. It can be used to determine if a given configuration is sufficiently accurate for the application.

Returns

• A baudrate with given settings.

LEUART_BaudrateGet#

uint32_t LEUART_BaudrateGet (LEUART_TypeDef * leuart)

Get the current baudrate for LEUART.

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

Returns

• The current baudrate.

LEUART_BaudrateSet#

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

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

Note

• The baudrate setting 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.

LEUART_Enable#

void LEUART_Enable (LEUART_TypeDef * leuart, LEUART_Enable_TypeDef enable)

Enable/disable the LEUART receiver and/or transmitter.

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

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.

LEUART_FreezeEnable#

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 the 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 unnecessary stalling.

LEUART_Init#

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

Initialize LEUART.

This function will configure basic settings to operate in normal asynchronous mode. Consider using LEUART_Reset() prior to this function if the 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 for the LEUART to work as intended. (When configuring pins consider the sequence of configuration 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.

LEUART_Reset#

void LEUART_Reset (LEUART_TypeDef * leuart)

Reset LEUART to the same state that it was in after a hardware reset.

LEUART_Rx#

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. See LEUART_RxExt() for reception of 9 bit frames.

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

Note

• This function will stall if the buffer is empty until data is received.

Returns

• Data received.

LEUART_RxExt#

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.

Returns

• Data received.

LEUART_Tx#

void LEUART_Tx (LEUART_TypeDef * leuart, uint8_t data)

Transmit one frame.

Depending on the frame length configuration, 8 (least significant) bits from data are transmitted. If the frame length is 9, 8 bits are transmitted from data and one bit as specified by the CTRL register, BIT8DV field. See 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 a part of the specified frame bit length.

Note

• This function will stall if buffer is full until the buffer becomes available.

LEUART_TxExt#

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 a part of the specified frame bit length.

Note

• This function will stall if the buffer is full until the buffer becomes available.

LEUART_TxDmaInEM2Enable#

void LEUART_TxDmaInEM2Enable (LEUART_TypeDef * leuart, bool enable)

Enables handling of LEUART TX by DMA in EM2.

LEUART_RxDmaInEM2Enable#

void LEUART_RxDmaInEM2Enable (LEUART_TypeDef * leuart, bool enable)

Enables handling of LEUART RX by DMA in EM2.

LEUART_IntClear#

void LEUART_IntClear (LEUART_TypeDef * leuart, uint32_t flags)

Clear one or more pending LEUART interrupts.

LEUART_IntDisable#

void LEUART_IntDisable (LEUART_TypeDef * leuart, uint32_t flags)

Disable one or more LEUART interrupts.

LEUART_IntEnable#

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. To ignore a pending interrupt, consider using LEUART_IntClear() prior to enabling the interrupt.

LEUART_IntGet#

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.

Returns

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

LEUART_IntGetEnabled#

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.

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 LEUART module (LEUARTx_IF_nnn).

LEUART_IntSet#

void LEUART_IntSet (LEUART_TypeDef * leuart, uint32_t flags)

Set one or more pending LEUART interrupts from SW.

LEUART_StatusGet#

uint32_t LEUART_StatusGet (LEUART_TypeDef * leuart)

Get LEUART STATUS register.

Returns

• STATUS register value.

LEUART_RxDataGet#

uint8_t LEUART_RxDataGet (LEUART_TypeDef * leuart)

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

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

Note

• Since this function does not check if 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., 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.

Returns

• Data received.

LEUART_RxDataXGet#

uint16_t LEUART_RxDataXGet (LEUART_TypeDef * leuart)

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

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

Note

• Since this function does not check if 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., 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.

Returns

• Data received.