Functions
fsp_err_t	R_UARTA_Open (uart_ctrl_t const p_api_ctrl, uart_cfg_t const const p_cfg)

fsp_err_t	R_UARTA_Close (uart_ctrl_t *const p_api_ctrl)

fsp_err_t	R_UARTA_Read (uart_ctrl_t const p_api_ctrl, uint8_t const p_dest, uint32_t const bytes)

fsp_err_t	R_UARTA_Write (uart_ctrl_t const p_api_ctrl, uint8_t const const p_src, uint32_t const bytes)

fsp_err_t	R_UARTA_CallbackSet (uart_ctrl_t const p_api_ctrl, void(p_callback)(uart_callback_args_t ), void const const p_context, uart_callback_args_t *const p_callback_memory)

fsp_err_t	R_UARTA_BaudSet (uart_ctrl_t const p_api_ctrl, void const const p_baud_setting)

fsp_err_t	R_UARTA_InfoGet (uart_ctrl_t const p_api_ctrl, uart_info_t const p_info)

fsp_err_t	R_UARTA_Abort (uart_ctrl_t *const p_api_ctrl, uart_dir_t communication_to_abort)

fsp_err_t	R_UARTA_ReadStop (uart_ctrl_t const p_api_ctrl, uint32_t p_remaining_bytes)

fsp_err_t	R_UARTA_BaudCalculate (uint32_t baudrate, uint32_t baud_rate_percent_error_x1000, uarta_clock_source_t clock_source, uarta_baud_setting_t *const p_baud_setting)

Detailed Description

Driver for the UARTA peripheral on RA MCUs. This module implements the UART Interface.

Overview

Features

The UARTA module supports the following features:

Full-duplex UART communication
Interrupt-driven data transmission and reception
Baud-rate change at run-time
Integration with the DTC transfer module
Abort in-progress read/write operations
MSB or LSB first transfer selectable
Inversion control of communication logic level provided
Clock output function (Not available on all MCUs)

Configuration

Build Time Configurations for r_uarta

The following build time configurations are defined in fsp_cfg/r_uarta_cfg.h:

Configuration	Options	Default	Description
Parameter Checking	Default (BSP) Enabled Disabled	Default (BSP)	If selected code for parameter checking is included in the build.
DTC Support	MCU Specific Options		Enable DTC support for the UARTA module.
Receive Error Interrupt Mode	Disabled Enabled	Enabled	Selection receive interrupt mode . Disabled: The UARTA0_ERRI interrupt is generated when a reception error occurs. Enabled: The UARTA0_RXI interrupt is generated when a reception error occurs.

Configurations for Connectivity > UART (r_uarta)

This module can be added to the Stacks tab via New Stack > Connectivity > UART (r_uarta).

Configuration	Options	Default	Description
General
Name	Name must be a valid C symbol	g_uart0	Module name.
Channel	Value must be a non-negative integer	0	Select the UARTA channel.
Data Bits	8bits 7bits 5bits	8bits	Select the number of bits per word.
Parity	None Zero Odd Even	None	Select the parity mode.
Stop Bits	1bit 2bits	1bit	Select the number of stop bits. Note: For the receive data, only the first 1 bit of the stop bits is checked regardless of the stop bit length.
Baud
Baud Rate	Value must be an integer greater than 0	115200	Enter the desired baud rate. If the requested baud rate cannot be achieved, the settings with the smallest percent error are used. The theoretical calculated baud rate and percent error are printed in a comment in the generated baud_setting_t structure.
Extra
Transfer Order	LSB first MSB first	LSB first	Selection of the transmission/reception order.
Transfer level	Positive logic Negative logic	Positive logic	Selection of the transmission/reception level.
Clock output	MCU Specific Options		Enable Clock output
Interrupts
Callback	Name must be a valid C symbol	NULL	A user callback function can be provided. If this callback function is provided, it will be called from the interrupt service routine (ISR).
Receive Interrupt Priority	MCU Specific Options		Select the receive interrupt priority.
Transmit Interrupt Priority	MCU Specific Options		Select the transmit interrupt priority.
Error Interrupt Priority	MCU Specific Options		Select the error interrupt priority.

Clock Configuration

The baud-rate clock generator can be selected from the clock source MOSC, HOCO, MOCO, SOSC/LOCO.

Pin Configuration

This module uses TXDA and RXDA pin to communicate to external devices.

Usage Notes

Limitations

Reception is still enabled after uart_api_t::communicationAbort API is called. Any characters received after abort and before the next call to read will arrive via the callback function with event UART_EVENT_RX_CHAR.
The UARTA module does not have CTS or RTS signals.

DTC Limitations

DTC support is available for reception, but labeled as [Not recommended]. This is because the UART bytes are received asynchronously. Bytes can be received between calls to R_UARTA_Read(). The logic required to combine bytes received through R_UARTA_Read() (UART_EVENT_RX_COMPLETE) and bytes received between calls (UART_EVENT_RX_CHAR) is complex. Reception length may also be unknown, and the driver will not issue an interrupt unless the entire DTC buffer is filled.
Transfer size must be less than or equal to 64K bytes if DTC interface is used for transfer. uart_api_t::infoGet API can be used to get the max transfer size allowed.

Examples

UARTA Example

uint8_t           g_dest[TRANSFER_LENGTH];
uint8_t           g_src[TRANSFER_LENGTH];
uint8_t           g_out_of_band_received[TRANSFER_LENGTH];
volatile uint32_t g_transfer_complete = 0;
volatile uint32_t g_receive_complete  = 0;
uint32_t          g_out_of_band_index = 0;
void r_uarta_basic_example (void)
{
    /* Initialize p_src to known data */
    for (uint32_t i = 0; i < TRANSFER_LENGTH; i++)
    {
        g_src[i] = (uint8_t) ('A' + (i % 26));
    }
    /* Open the transfer instance with initial configuration. */
    fsp_err_t err = R_UARTA_Open(&g_uart0_ctrl, &g_uart0_cfg);
    assert(FSP_SUCCESS == err);
    err = R_UARTA_Read(&g_uart0_ctrl, g_dest, TRANSFER_LENGTH);
    assert(FSP_SUCCESS == err);
    err = R_UARTA_Write(&g_uart0_ctrl, g_src, TRANSFER_LENGTH);
    assert(FSP_SUCCESS == err);
    while (!g_transfer_complete)
    {
    }
    while (!g_receive_complete)
    {
    }
}
void example_callback (uart_callback_args_t * p_args)
{
    /* Handle the UART event */
    switch (p_args->event)
    {
        /* Received a character */
        case UART_EVENT_RX_CHAR:
        {
            /* Only put the next character in the receive buffer if there is space for it */
            if (sizeof(g_out_of_band_received) > g_out_of_band_index)
            {
                /* Write either the next one or two bytes depending on the receive data size */
                if (UART_DATA_BITS_8 >= g_uart0_cfg.data_bits)
                {
                    g_out_of_band_received[g_out_of_band_index++] = (uint8_t) p_args->data;
                }
                else
                {
                    uint16_t * p_dest = (uint16_t *) &g_out_of_band_received[g_out_of_band_index];
                    *p_dest              = (uint16_t) p_args->data;
                    g_out_of_band_index += 2;
                }
            }
            break;
        }
        /* Receive complete */
        case UART_EVENT_RX_COMPLETE:
        {
            g_receive_complete = 1;
            break;
        }
        /* Transmit complete */
        case UART_EVENT_TX_COMPLETE:
        {
            g_transfer_complete = 1;
            break;
        }
        default:
        {
        }
    }
}

UARTA Baud Set Example

#define UARTA_BAUDRATE_19200                 (19200)
#define UARTA_BAUDRATE_ERROR_PERCENT_4740    (4740)
void r_uarta_baud_example (void)
{
    uarta_baud_setting_t baud_setting;
    uint32_t             baud_rate         = UARTA_BAUDRATE_19200;
    uint32_t             error_rate_x_1000 = UARTA_BAUDRATE_ERROR_PERCENT_4740;
    uarta_clock_source_t clock_source      = UARTA_CLOCK_SOURCE_HOCO;
    fsp_err_t err = R_UARTA_BaudCalculate(baud_rate, error_rate_x_1000, clock_source, &baud_setting);
    assert(FSP_SUCCESS == err);
    err = R_UARTA_BaudSet(&g_uart0_ctrl, (void *) &baud_setting);
    assert(FSP_SUCCESS == err);
}

Data Structures
struct	uarta_baud_setting_t

struct	uarta_extended_cfg_t

struct	uarta_instance_ctrl_t

Enumerations
enum	uarta_clock_source_t

enum	uarta_clock_div_t

enum	uarta_clock_out_t

enum	uarta_dir_bit_t

enum	uarta_alv_bit_t

Data Structure Documentation

◆ uarta_baud_setting_t

struct uarta_baud_setting_t

Register settings to acheive a desired baud rate and modulation duty.

Data Fields
union uarta_baud_setting_t	__unnamed__
uint8_t	brgca	Baud rate generator control setting.
uint16_t	delay_time	Delay time (us) required to enable TX at open.

◆ uarta_extended_cfg_t

struct uarta_extended_cfg_t

UART on UARTA device Configuration

Data Fields
uarta_dir_bit_t	transfer_dir	Transmission/reception order configuration.
uarta_alv_bit_t	transfer_level	Transmission/reception level configuration.
uarta_clock_out_t	clock_output	Disable/Enable clock output.
uarta_baud_setting_t *	p_baud_setting	Register settings for a desired baud rate.

◆ uarta_instance_ctrl_t

struct uarta_instance_ctrl_t

UARTA instance control block.

Enumeration Type Documentation

◆ uarta_clock_source_t

enum uarta_clock_source_t

Enumeration for UARTA clock source

Enumerator
UARTA_CLOCK_SOURCE_SOSC_LOCO	SOSC/LOCO.
UARTA_CLOCK_SOURCE_LOCO	LOCO.
UARTA_CLOCK_SOURCE_MOSC	MOSC.
UARTA_CLOCK_SOURCE_HOCO	HOCO.
UARTA_CLOCK_SOURCE_MOCO	MOCO.
UARTA_CLOCK_SOURCE_SOSC	SOSC.

◆ uarta_clock_div_t

enum uarta_clock_div_t

Enumeration for UARTA clock divider

Enumerator
UARTA_CLOCK_DIV_1	fSEL/1
UARTA_CLOCK_DIV_2	fSEL/2
UARTA_CLOCK_DIV_4	fSEL/4
UARTA_CLOCK_DIV_8	fSEL/8
UARTA_CLOCK_DIV_16	fSEL/16
UARTA_CLOCK_DIV_32	fSEL/32
UARTA_CLOCK_DIV_64	fSEL/64
UARTA_CLOCK_DIV_COUNT	Total number of clock divider options.

◆ uarta_clock_out_t

enum uarta_clock_out_t

Enabled/Disabled Clock output

Enumerator
UARTA_CLOCK_OUTPUT_DISABLED	Disables CLKAn output.
UARTA_CLOCK_OUTPUT_ENABLED	Enables CLKAn output.

◆ uarta_dir_bit_t

enum uarta_dir_bit_t

Transmission/reception order configuration.

Enumerator
UARTA_DIR_BIT_MSB_FIRST	MSB first.
UARTA_DIR_BIT_LSB_FIRST	LSB first.

◆ uarta_alv_bit_t

enum uarta_alv_bit_t

Transmission/reception level configuration.

Enumerator
UARTA_ALV_BIT_POSITIVE_LOGIC	Positive logic (wait state = high level, start bit = low level, stop bit = high level)
UARTA_ALV_BIT_NEGATIVE_LOGIC	Negative logic (wait state = low level, start bit = high level, stop bit = low level)

Function Documentation

◆ R_UARTA_Open()

fsp_err_t R_UARTA_Open	(	uart_ctrl_t *const	p_api_ctrl,
		uart_cfg_t const *const	p_cfg
	)

Configures the UARTA driver based on the input configurations. If transmission/reception is enabled at compile time, transmission/reception is enabled at the end of this function. Implements uart_api_t::open

Return values

FSP_SUCCESS	Channel opened successfully.
FSP_ERR_ASSERTION	Pointer to UARTA control block or configuration structure is NULL.
FSP_ERR_IP_CHANNEL_NOT_PRESENT	The requested channel does not exist on this MCU.
FSP_ERR_INVALID_ARGUMENT	Invalid clock select (f_UTA0) and baudrate configuration.
FSP_ERR_ALREADY_OPEN	Control block has already been opened or channel is being used by another instance. Call close() then open() to reconfigure.

Returns

See Common Error Codes or functions called by this function for other possible return codes. This function calls:

transfer_api_t::open

◆ R_UARTA_Close()

fsp_err_t R_UARTA_Close ( uart_ctrl_t *const p_api_ctrl )

Aborts any in progress transfers. Disables interrupts, receiver, and transmitter. Closes lower level transfer drivers if used. Removes power. Implements uart_api_t::close

Return values

FSP_SUCCESS	Channel successfully closed.
FSP_ERR_ASSERTION	Pointer to UARTA control block is NULL.
FSP_ERR_NOT_OPEN	The control block has not been opened

◆ R_UARTA_Read()

fsp_err_t R_UARTA_Read	(	uart_ctrl_t *const	p_api_ctrl,
		uint8_t *const	p_dest,
		uint32_t const	bytes
	)

Receives user specified number of bytes into destination buffer pointer. Implements uart_api_t::read

Return values

FSP_SUCCESS	Data reception successfully ends.
FSP_ERR_ASSERTION	Pointer to UARTA control block is NULL. Number of transfers outside the max or min boundary when transfer instance used
FSP_ERR_NOT_OPEN	The control block has not been opened
FSP_ERR_IN_USE	A previous read operation is still in progress.
FSP_ERR_UNSUPPORTED	UARTA_CFG_RX_ENABLE is set to 0

Returns

See Common Error Codes or functions called by this function for other possible return codes. This function calls:

transfer_api_t::reset

◆ R_UARTA_Write()

fsp_err_t R_UARTA_Write	(	uart_ctrl_t *const	p_api_ctrl,
		uint8_t const *const	p_src,
		uint32_t const	bytes
	)

Transmits user specified number of bytes from the source buffer pointer. Implements uart_api_t::write

Return values

FSP_SUCCESS	Data transmission finished successfully.
FSP_ERR_ASSERTION	Pointer to UARTA control block is NULL. Number of transfers outside the max or min boundary when transfer instance used
FSP_ERR_NOT_OPEN	The control block has not been opened
FSP_ERR_IN_USE	A UARTA transmission is in progress
FSP_ERR_UNSUPPORTED	UART_CFG_TX_ENABLE is set to 0

Returns

See Common Error Codes or functions called by this function for other possible return codes. This function calls:

transfer_api_t::reset

◆ R_UARTA_CallbackSet()

fsp_err_t R_UARTA_CallbackSet	(	uart_ctrl_t *const	p_api_ctrl,
		void()(uart_callback_args_t )	p_callback,
		void const *const	p_context,
		uart_callback_args_t *const	p_callback_memory
	)

Updates the user callback and has option of providing memory for callback structure. Implements uart_api_t::callbackSet

Return values

FSP_SUCCESS	Callback updated successfully.
FSP_ERR_ASSERTION	A required pointer is NULL.
FSP_ERR_NOT_OPEN	The control block has not been opened.

◆ R_UARTA_BaudSet()

fsp_err_t R_UARTA_BaudSet	(	uart_ctrl_t *const	p_api_ctrl,
		void const *const	p_baud_setting
	)

Updates the baud rate using the clock selected in Open. p_baud_setting is a pointer to a uarta_baud_setting_t structure. Implements uart_api_t::baudSet

Warning: This terminates any in-progress transmission.

Return values

FSP_SUCCESS	Baud rate was successfully changed.
FSP_ERR_ASSERTION	Pointer to UARTA control block is NULL or the UART is not configured to use the internal clock.
FSP_ERR_INVALID_ARGUMENT	Invalid clock select (f_UTA0) and baudrate configuration.
FSP_ERR_NOT_OPEN	The control block has not been opened

◆ R_UARTA_InfoGet()

fsp_err_t R_UARTA_InfoGet	(	uart_ctrl_t *const	p_api_ctrl,
		uart_info_t *const	p_info
	)

Provides the driver information, including the maximum number of bytes that can be received or transmitted at a time. Implements uart_api_t::infoGet

Return values

FSP_SUCCESS	Information stored in provided p_info.
FSP_ERR_ASSERTION	Pointer to UART control block is NULL.
FSP_ERR_NOT_OPEN	The control block has not been opened

◆ R_UARTA_Abort()

fsp_err_t R_UARTA_Abort	(	uart_ctrl_t *const	p_api_ctrl,
		uart_dir_t	communication_to_abort
	)

Provides API to abort ongoing transfer. Transmission is aborted after the current character is transmitted. Reception is still enabled after abort(). Any characters received after abort() and before the transfer is reset in the next call to read(), will arrive via the callback function with event UART_EVENT_RX_CHAR. Implements uart_api_t::communicationAbort

Return values

FSP_SUCCESS	UARTA transaction aborted successfully.
FSP_ERR_ASSERTION	Pointer to UARTA control block is NULL.
FSP_ERR_NOT_OPEN	The control block has not been opened.
FSP_ERR_UNSUPPORTED	The requested Abort direction is unsupported.

Returns: See Common Error Codes or functions called by this function for other possible return codes. This function calls: transfer_api_t::disable

◆ R_UARTA_ReadStop()

fsp_err_t R_UARTA_ReadStop	(	uart_ctrl_t *const	p_api_ctrl,
		uint32_t *	p_remaining_bytes
	)

Provides API to abort ongoing read. Reception is still enabled after abort(). Any characters received after abort() and before the transfer is reset in the next call to read(), will arrive via the callback function with event UART_EVENT_RX_CHAR. Implements uart_api_t::readStop

Return values

FSP_SUCCESS	UARTA transaction aborted successfully.
FSP_ERR_ASSERTION	Pointer to UARTA control block is NULL.
FSP_ERR_NOT_OPEN	The control block has not been opened.
FSP_ERR_UNSUPPORTED	The requested Abort direction is unsupported.

Returns: See Common Error Codes or functions called by this function for other possible return codes. This function calls: transfer_api_t::disable

◆ R_UARTA_BaudCalculate()

fsp_err_t R_UARTA_BaudCalculate	(	uint32_t	baudrate,
		uint32_t	baud_rate_percent_error_x1000,
		uarta_clock_source_t	clock_source,
		uarta_baud_setting_t *const	p_baud_setting
	)

Calculates baud rate register settings. Evaluates and determines the best possible settings set to the baud rate related registers.

Parameters

[in]	baudrate	Baud rate [bps]. For example, 19200, 57600, 115200, etc.
[in]	baud_rate_percent_error_x1000	Max baud rate error. At most baud_rate_percent_error x 1000 required for module to function. Absolute max baud_rate_error is 4740 (4.74%).
[in]	clock_source	Clock Source. Required for module to generate baudrate. The clock sources can be select include UARTA_CLOCK_SOURCE_MOSC, UARTA_CLOCK_SOURCE_HOCO, UARTA_CLOCK_SOURCE_MOCO, UARTA_CLOCK_SOURCE_SOSC_LOCO.
[out]	p_baud_setting	Baud setting information stored here if successful

Return values

FSP_SUCCESS	Baud rate is set successfully
FSP_ERR_ASSERTION	Null pointer
FSP_ERR_INVALID_ARGUMENT	Argument is out of available range, baud rate is '0'.
FSP_ERR_INVALID_RATE	Baud rate error is outside the range or the baud rate could not be set given the current clock source.

Functions

Detailed Description

Overview

Features

Configuration

Build Time Configurations for r_uarta

Configurations for Connectivity > UART (r_uarta)

Clock Configuration

Pin Configuration

Usage Notes

Limitations

DTC Limitations

Examples

UARTA Example

UARTA Baud Set Example

Data Structures

Enumerations

Data Structure Documentation

◆ uarta_baud_setting_t

◆ uarta_extended_cfg_t

◆ uarta_instance_ctrl_t

Enumeration Type Documentation

◆ uarta_clock_source_t

◆ uarta_clock_div_t

◆ uarta_clock_out_t

◆ uarta_dir_bit_t

◆ uarta_alv_bit_t

Function Documentation

◆ R_UARTA_Open()

◆ R_UARTA_Close()

◆ R_UARTA_Read()

◆ R_UARTA_Write()

◆ R_UARTA_CallbackSet()

◆ R_UARTA_BaudSet()

◆ R_UARTA_InfoGet()

◆ R_UARTA_Abort()

◆ R_UARTA_ReadStop()

◆ R_UARTA_BaudCalculate()