UART Configuration Commands Reference#

UC Requirement: The default UART settings must be made configurable through the Studio UC interface, so that customers may change them as needed.

UART Configuration AT Commands#

This section describes the following AT commands for UART configuration functionality on the SiWx91x device:

uart-baud#

Re-configure the baud rate in the UART driver on the SiWx91x device for its communication with the AT commands external host.

Command Format#

at+uart-baud=<baud-rate>

Related SDK API#

sl_si91x_usart_set_configuration

Pre-conditions#

None

Parameters#

baud-rate#

Baud rate for USART communication in bits per second (bps).

Response#

Notes#

Examples#

at+uart-baud=230400        # Update baud rate to 230,400 bps
OK

uart-databits#

Re-configure the data bits in the UART driver on the SiWx91x device for its communication with the AT commands external host.

Command Format#

at+uart-databits=<data-bits>

Related SDK API#

sl_si91x_usart_set_configuration

Pre-conditions#

None

Parameters#

data-bits#

Number of data bits. Contains a numeric value that corresponds to one of the values of the enum usart_databits_typedef_t.

Note: The values of the usart_databits_typedef_t enum are not in strict numerical order. Refer to the sl_si91x_usart.h and Driver_USART.h files for the complete list of valid values and their numerical values.

Response#

Notes#

  • The external host application must re-configure its UART driver to match the new data bits configured on the SiWx91x device.

  • During the boot up of the SiWx91x device, the following steps are performed:

  • Use the uart-conf? command to view the current SiWx91x UART configuration before using this or other UART commands to modify specific settings.

  • This command updates the data bits setting in the sl_si91x_usart_control_config_t structure and applies the new setting by invoking the sl_si91x_usart_set_configuration API.

Examples#

at+uart-databits=1792        # Update data bits to 7
                             # ARM_USART_DATA_BITS_7 = (7UL << ARM_USART_DATA_BITS_Pos) = (7UL << 8) = 1792
OK

uart-stopbits#

Re-configure the stop bits in the UART driver on the SiWx91x device for its communication with the AT commands external host.

Command Format#

at+uart-stopbits=<stop-bits>

Related SDK API#

sl_si91x_usart_set_configuration

Pre-conditions#

None

Parameters#

stop-bits#

Number of stop bits. Contains a numeric value that corresponds to one of the values of the enum usart_stopbit_typedef_t.

Note: The values of the usart_stopbit_typedef_t enum are not in strict numerical order. Refer to the sl_si91x_usart.h and Driver_USART.h files for the complete list of valid values and their numerical values.

Response#

Notes#

  • The external host application must re-configure its UART driver to match the new stop bits configured on the SiWx91x device.

  • During the boot up of the SiWx91x device, the following steps are performed:

  • Use the uart-conf? command to view the current SiWx91x UART configuration before using this or other UART commands to modify specific settings.

  • This command updates the stop bits setting in the sl_si91x_usart_control_config_t structure and applies the new setting by invoking the sl_si91x_usart_set_configuration API.

Examples#

at+uart-stopbits=16384        # Update stop bits to 2
                              # ARM_USART_STOP_BITS_2 = (1UL << ARM_USART_STOP_BITS_Pos) = (1UL << 14) = 16384
OK

uart-parity#

Re-configure the parity setting in the UART driver on the SiWx91x device for its communication with the AT commands external host.

Command Format#

at+uart-parity=<parity>

Related SDK API#

sl_si91x_usart_set_configuration

Pre-conditions#

None

Parameters#

parity#

Parity setting for the UART interface. Contains a numeric value that corresponds to one of the values of the enum usart_parity_typedef_t.

Note: The values of the usart_parity_typedef_t enum are not in strict numerical order. Refer to the sl_si91x_usart.h and Driver_USART.h files for the complete list of valid values and their numerical values.

Response#

Notes#

  • The external host application must re-configure its UART driver to match the new parity setting configured on the SiWx91x device.

  • During the boot up of the SiWx91x device, the following steps are performed:

  • Use the uart-conf? command to view the current SiWx91x UART configuration before using this or other UART commands to modify specific settings.

  • This command updates the parity setting in the sl_si91x_usart_control_config_t structure and applies the new setting by invoking the sl_si91x_usart_set_configuration API.

Examples#

at+uart-parity=8192        # Update parity to odd
                           # ARM_USART_PARITY_ODD = (2UL << ARM_USART_PARITY_Pos) = (2UL << 12) = 8192
OK

uart-hwflowctrl#

Re-configure the hardware flow control setting in the UART driver on the SiWx91x device for its communication with the AT commands external host.

Command Format#

at+uart-hwflowctrl=<hw-flow-control>

Related SDK API#

sl_si91x_usart_set_configuration

Pre-conditions#

None

Parameters#

hw-flow-control#

Hardware flow control setting for the UART interface. Contains a numeric value that corresponds to one of the values of the enum usart_hwflowcontol_typedef_t.

Note: The values of the usart_hwflowcontol_typedef_t enum are not in strict numerical order. Refer to the sl_si91x_usart.h and Driver_USART.h files for the complete list of valid values and their numerical values.

Response#

Notes#

  • The external host application must re-configure its UART driver to match the new hardware flow control setting configured on the SiWx91x device.

  • During the boot up of the SiWx91x device, the following steps are performed:

  • Use the uart-conf? command to view the current SiWx91x UART configuration before using this or other UART commands to modify specific settings.

  • This command updates the hardware flow control setting in the sl_si91x_usart_control_config_t structure and applies the new setting by invoking the sl_si91x_usart_set_configuration API.

Examples#

at+uart-hwflowctrl=196608        # Update hardware flow control to RTS + CTS (receive + transmit)
                                 # ARM_USART_FLOW_CONTROL_RTS_CTS = (3UL << ARM_USART_FLOW_CONTROL_Pos) = (3UL << 16) = 196608
OK

uart-conf?#

Query the current configuration settings for the UART driver on the SiWx91x device for its communication with the AT commands external host.

Command Format#

at+uart-conf?

Related SDK API#

sl_si91x_usart_get_configurations

Pre-conditions#

None

Parameters#

None

Response#

  • OK <baud-rate> <mode> <parity> <stop-bits> <hw-flow-control> <data-bits> <misc-control> <usart-module> <config-enable> <synch-mode> on success, where:

    • <baud-rate> is the current baud rate for USART communication in bits per second (bps)

    • <mode> is the current USART mode of operation (values from usart_mode_typedef_t)

    • <parity> is the current parity bit configuration (values from usart_parity_typedef_t)

    • <stop-bits> is the current number of stop bits (values from usart_stopbit_typedef_t)

    • <hw-flow-control> is the current hardware flow control configuration (values from usart_hwflowcontol_typedef_t)

    • <data-bits> is the current number of data bits (values from usart_databits_typedef_t)

    • <misc-control> is the number of current miscellaneous control options (values from usart_misc_control_typedef_t)

    • <usart-module> is the current USART module identifier

    • <config-enable> is the current configuration enable setting (0 = disabled, 1 = enabled)

    • <synch-mode> is the current synchronous mode setting (0 = asynchronous, 1 = synchronous)

  • ERROR <error-code> in case of failure. Possible error codes are the same as those returned by the sl_si91x_usart_get_configurations API.

Notes#

  • This command is useful for viewing the current UART configuration before making changes with other UART commands.

  • The enum values are not in strict numerical order. The actual numerical values of all enum parameters can be found in the sl_si91x_usart.h and Driver_USART.h files. For example, parity=odd corresponds to ARM_USART_PARITY_ODD = (2UL << 12) = 8192.

Examples#

at+uart-conf?        # Query current UART configuration
OK 115200 1 8192 16384 196608 1792 21 0 1 0
# baud-rate=115,200 bps, mode=asynchronous, parity=odd, stop-bits=2, hw-flow-control=RTS+CTS, data-bits=7, misc-control=TX control, USART module=USART0