USART - Synchronous/Asynchronous Serial#

sl_hal_usart_data_bits_t#

sl_hal_usart_data_bits_t

Databit selection.

sl_hal_usart_ovs_t#

sl_hal_usart_ovs_t

Oversampling selection, used for asynchronous operation.

sl_hal_usart_parity_t#

sl_hal_usart_parity_t

Parity selection, mainly used for asynchronous operation.

sl_hal_usart_stop_bits_t#

sl_hal_usart_stop_bits_t

Stop bits selection, used for asynchronous operation.

sl_hal_usart_majority_vote_t#

sl_hal_usart_majority_vote_t

Majority vote enable.

sl_hal_usart_hw_flow_control_t#

sl_hal_usart_hw_flow_control_t

Hardware Flow Control Selection.

sl_hal_usart_clock_mode_t#

sl_hal_usart_clock_mode_t

Clock polarity/phase mode.

sl_hal_usart_irda_pulse_width_t#

sl_hal_usart_irda_pulse_width_t

Pulse width selection for IrDA mode.

sl_hal_usart_i2s_format_t#

sl_hal_usart_i2s_format_t

I2S format selection.

sl_hal_usart_i2s_justify_t#

sl_hal_usart_i2s_justify_t

I2S frame data justify.

sl_hal_usart_init_async#

void sl_hal_usart_init_async (USART_TypeDef * usart, const sl_hal_usart_async_init_t * init)

Initialize USART/UART for normal asynchronous mode.

This function will configure basic settings to operate in normal asynchronous mode.

A special control setup not covered by this function must be done after using this function by direct modification of the CTRL register.

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

sl_hal_usart_async_calculate_baudrate#

uint32_t sl_hal_usart_async_calculate_baudrate (uint32_t ref_freq, uint32_t clk_div, sl_hal_usart_ovs_t ovs)

Calculate baudrate for USART/UART given reference frequency, clock division, and oversampling rate.

This function returns the baudrate that a USART/UART module will use if configured with the given frequency, clock divider, and mode. 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

• Baudrate with given settings.

sl_hal_usart_async_calculate_clock_div#

uint32_t sl_hal_usart_async_calculate_clock_div (uint32_t ref_freq, uint32_t baudrate, sl_hal_usart_ovs_t ovs)

Calculate UART clock divider using given reference frequency, oversampling and baudrate.

Returns

• USART clock divider for desired baud rate.

sl_hal_usart_init_sync#

void sl_hal_usart_init_sync (USART_TypeDef * usart, const sl_hal_usart_sync_init_t * init)

Initialize USART for synchronous mode.

This function will configure basic settings to operate in synchronous mode.

A special control setup not covered by this function must be done after using this function by direct modification of the CTRL register.

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

sl_hal_usart_sync_calculate_baudrate#

uint32_t sl_hal_usart_sync_calculate_baudrate (uint32_t ref_freq, uint32_t clk_div)

Calculate baudrate for USART/UART (sync mode) given reference frequency, clock division.

This function returns the baudrate that a USART/UART module will use if configured with the given frequency, clock divider, and mode. 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

• Baudrate with given settings.

sl_hal_usart_sync_calculate_clock_div#

uint32_t sl_hal_usart_sync_calculate_clock_div (uint32_t ref_freq, uint32_t baudrate)

Calculate UART (sync mode) clock divider using given reference frequency and baudrate.

Returns

• USART clock divider for desired baud rate.

sl_hal_usart_init_irda#

void sl_hal_usart_init_irda (USART_TypeDef * usart, const sl_hal_usart_irda_init_t * init)

Initialize USART for asynchronous IrDA mode.

This function will configure basic settings to operate in asynchronous IrDA mode.

A special control setup not covered by this function must be done after using this function by direct modification of the CTRL and IRCTRL registers.

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

Note

• Not all USART instances support IrDA.

sl_hal_usart_init_i2s#

void sl_hal_usart_init_i2s (USART_TypeDef * usart, const sl_hal_usart_i2s_init_t * init)

Initialize USART for I2S mode.

This function will configure basic settings to operate in I2S mode.

A special control setup not covered by this function must be done after using this function by direct modification of the CTRL and I2SCTRL registers.

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

Note

• This function does not apply to all USART's.

sl_hal_usart_reset#

void sl_hal_usart_reset (USART_TypeDef * usart)

Reset USART/UART to the same state that it was in after a hardware reset.

sl_hal_usart_tx#

void sl_hal_usart_tx (USART_TypeDef * usart, uint8_t data)

Transmit one 4-9 bit frame.

Depending on the frame length configuration, 4-8 (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 CTRL register, BIT8DV field. See sl_hal_usart_tx_ext() 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 a specified frame bit length.

Note

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

sl_hal_usart_spi_transfer#

uint8_t sl_hal_usart_spi_transfer (USART_TypeDef * usart, uint8_t data)

Perform one 8 bit frame SPI transfer.

Note

• This function will stall if the transmit buffer is full. When a transmit buffer becomes available, data is written and the function will wait until data is fully transmitted. The SPI return value is then read out and returned.

Returns

• Data received.

sl_hal_usart_tx_double#

void sl_hal_usart_tx_double (USART_TypeDef * usart, uint16_t data)

Transmit two 4-9 bit frames or one 10-16 bit frame.

Depending on the frame length configuration, 4-8 (least significant) bits from each byte in data are transmitted. If frame length is 9, 8 bits are transmitted from each byte in data adding one bit as specified by the CTRL register, BIT8DV field, to each byte. See sl_hal_usart_tx_double_ext() for transmitting two 9 bit frames with full control of all 9 bits.

If the frame length is 10-16, 10-16 (least significant) bits from data are transmitted.

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

Note

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

sl_hal_usart_tx_double_ext#

void sl_hal_usart_tx_double_ext (USART_TypeDef * usart, uint32_t data)

Transmit two 4-9 bit frames or one 10-16 bit frame with extended control.

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

Note

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

• If the frame length is 10-16 bits, 8 data bits are taken from the least significant 16 bit word and the remaining bits from the other 16 bit word.

• Additional control bits are available as documented in the reference manual (set to 0 if not used). For 10-16 bit frame length, these control bits are taken from the most significant 16 bit word.

sl_hal_usart_tx_ext#

void sl_hal_usart_tx_ext (USART_TypeDef * usart, uint16_t data)

Transmit one 4-9 bit frame with extended control.

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

Note

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

sl_hal_usart_enable_rx_prs_trigger#

void sl_hal_usart_enable_rx_prs_trigger (USART_TypeDef * usart, uint8_t channel)

Enable automatic enabling of reception using the PRS as a trigger.

sl_hal_usart_disable_rx_prs_trigger#

void sl_hal_usart_disable_rx_prs_trigger (USART_TypeDef * usart)

Disable automatic enabling of reception using the PRS as a trigger.

sl_hal_usart_enable_tx_prs_trigger#

void sl_hal_usart_enable_tx_prs_trigger (USART_TypeDef * usart, uint8_t channel)

Enable automatic enabling of transmission using the PRS as a trigger.

sl_hal_usart_disable_tx_prs_trigger#

void sl_hal_usart_disable_tx_prs_trigger (USART_TypeDef * usart)

Disable automatic enabling of transmission using the PRS as a trigger.

sl_hal_usart_async_set_clock_div#

void sl_hal_usart_async_set_clock_div (USART_TypeDef * usart, uint32_t clock_div)

Set UART mode clock divider.

sl_hal_usart_async_get_clock_div#

uint32_t sl_hal_usart_async_get_clock_div (USART_TypeDef * usart)

Get UART mode clock divider.

Returns

• Clock divider value.

sl_hal_usart_enable#

void sl_hal_usart_enable (USART_TypeDef * usart)

Enable USART.

sl_hal_usart_disable#

void sl_hal_usart_disable (USART_TypeDef * usart)

Disable USART.

sl_hal_usart_enable_rx#

void sl_hal_usart_enable_rx (USART_TypeDef * usart)

Enable USART receiver.

sl_hal_usart_disable_rx#

void sl_hal_usart_disable_rx (USART_TypeDef * usart)

Disable USART receiver.

sl_hal_usart_enable_tx#

void sl_hal_usart_enable_tx (USART_TypeDef * usart)

Enable USART transmitter.

sl_hal_usart_disable_tx#

void sl_hal_usart_disable_tx (USART_TypeDef * usart)

Disable USART transmitter.

sl_hal_usart_clear_rx#

void sl_hal_usart_clear_rx (USART_TypeDef * usart)

Clear RX FIFO.

sl_hal_usart_clear_tx#

void sl_hal_usart_clear_tx (USART_TypeDef * usart)

Clear TX FIFO.

sl_hal_usart_rx#

uint8_t sl_hal_usart_rx (USART_TypeDef * usart)

Receive one 4-8 bit frame, (or part of 10-16 bit frame).

This function is normally used to receive one frame when operating with frame length 4-8 bits. See sl_hal_usart_rx_ext() for reception of 9 bit frames.

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

Note

• This function will stall if the buffer is empty until data is received. Alternatively, the user can explicitly check whether data is available. If data is available, call sl_hal_usart_rx_data_get() to read the RXDATA register directly.

Returns

• Data received.

sl_hal_usart_rx_double#

uint16_t sl_hal_usart_rx_double (USART_TypeDef * usart)

Receive two 4-8 bit frames or one 10-16 bit frame.

This function is normally used to receive one frame when operating with frame length 10-16 bits. See sl_hal_usart_rx_double_ext() for reception of two 9 bit frames.

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

Note

• This function will stall if the buffer is empty until data is received. Alternatively, the user can explicitly check whether data is available. If data is available, call sl_hal_usart_rx_double_get() to read the RXDOUBLE register directly.

Returns

• Data received.

sl_hal_usart_rx_double_ext#

uint32_t sl_hal_usart_rx_double_ext (USART_TypeDef * usart)

Receive two 4-9 bit frames, or one 10-16 bit frame with extended information.

This function is normally used to receive one frame when operating with frame length 10-16 bits and additional RX status information is required.

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

Note

• This function will stall if buffer is empty until data is received. Alternatively, the user can explicitly check whether data is available. If data is available, call sl_hal_usart_rx_double_x_get() to read the RXDOUBLEX register directly.

Returns

• Data received.

sl_hal_usart_rx_ext#

uint16_t sl_hal_usart_rx_ext (USART_TypeDef * usart)

Receive one 4-9 bit frame (or part of 10-16 bit frame) with extended information.

This function is normally used to receive one frame when operating with frame length 4-9 bits and additional RX status information is required.

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

Note

• This function will stall if the buffer is empty until data is received. Alternatively, the user can explicitly check whether data is available. If data is available, call sl_hal_usart_rx_data_get() to read the RXDATAX register directly.

Returns

• Data received.

sl_hal_usart_rx_data_get#

uint8_t sl_hal_usart_rx_data_get (USART_TypeDef * usart)

Receive one 4-8 bit frame, (or part of 10-16 bit frame).

This function is used to quickly receive one 4-8 bits 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 sl_hal_usart_rx_ext() for reception of 9 bit frames.

Note

• Because 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., when handling an RXDATAV interrupt. The sl_hal_usart_rx() is normally a better choice if the validity of the RXDATA register is not certain.

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

Returns

• Data received.

sl_hal_usart_rx_double_get#

uint16_t sl_hal_usart_rx_double_get (USART_TypeDef * usart)

Receive two 4-8 bit frames, or one 10-16 bit frame.

This function is used to quickly receive one 10-16 bits frame or two 4-8 bit frames by reading the RXDOUBLE 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. This function is normally used to receive one frame when operating with frame length 10-16 bits. Please refer to sl_hal_usart_rx_double_x_get() for reception of two 9 bit frames.

Note

• Because this function does not check whether the RXDOUBLE 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 sl_hal_usart_rx_double() is normally a better choice if the validity of the RXDOUBLE register is not certain.

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

Returns

• Data received.

sl_hal_usart_rx_double_x_get#

uint32_t sl_hal_usart_rx_double_x_get (USART_TypeDef * usart)

Receive two 4-9 bit frames, or one 10-16 bit frame with extended information.

This function is used to quickly receive one 10-16 bits frame or two 4-9 bit frames by reading the RXDOUBLEX 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

• Because this function does not check whether the RXDOUBLEX 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 sl_hal_usart_rx_double_ext() is normally a better choice if the validity of the RXDOUBLEX register is not certain.

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

Returns

• Data received.

sl_hal_usart_rx_data_x_get#

uint16_t sl_hal_usart_rx_data_x_get (USART_TypeDef * usart)

Receive one 4-9 bit frame, (or part of 10-16 bit frame) with extended information.

This function is used to quickly receive one 4-9 bit frame, (or part of 10-16 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

• Because 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., when handling an RXDATAV interrupt. The sl_hal_usart_rx_ext() is normally a better choice if the validity of the RXDATAX register is not certain.

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

Returns

• Data received.

sl_hal_usart_clear_interrupts#

void sl_hal_usart_clear_interrupts (USART_TypeDef * usart, uint32_t flags)

Clear one or more pending USART interrupts.

sl_hal_usart_disable_interrupts#

void sl_hal_usart_disable_interrupts (USART_TypeDef * usart, uint32_t flags)

Disable one or more USART interrupts.

sl_hal_usart_enable_interrupts#

void sl_hal_usart_enable_interrupts (USART_TypeDef * usart, uint32_t flags)

Enable one or more USART 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 USART_IntClear() prior to enabling the interrupt.

sl_hal_usart_get_pending_interrupts#

uint32_t sl_hal_usart_get_pending_interrupts (USART_TypeDef * usart)

Get pending USART interrupt flags.

Note

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

Returns

• USART/UART interrupt source(s) pending. Returns one or more valid interrupt flags for the USART module (USART_IF_nnn) OR'ed together.

sl_hal_usart_get_enabled_pending_interrupts#

uint32_t sl_hal_usart_get_enabled_pending_interrupts (USART_TypeDef * usart)

Get enabled and pending USART 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 USART interrupt sources. The return value is the bitwise AND combination of

  • the OR combination of enabled interrupt sources in USARTx_IEN_nnn register (USARTx_IEN_nnn) and

  • the OR combination of valid interrupt flags of the USART module (USARTx_IF_nnn).

sl_hal_usart_set_interrupts#

void sl_hal_usart_set_interrupts (USART_TypeDef * usart, uint32_t flags)

Set one or more pending USART interrupts from SW.

sl_hal_usart_get_status#

uint32_t sl_hal_usart_get_status (USART_TypeDef * usart)

Get USART STATUS register.

Returns

• STATUS register value.