Functions
fsp_err_t	R_IICA_SLAVE_Open (i2c_slave_ctrl_t const p_api_ctrl, i2c_slave_cfg_t const const p_cfg)

fsp_err_t	R_IICA_SLAVE_Read (i2c_slave_ctrl_t const p_api_ctrl, uint8_t const p_dest, uint32_t const bytes)

fsp_err_t	R_IICA_SLAVE_Write (i2c_slave_ctrl_t const p_api_ctrl, uint8_t const p_src, uint32_t const bytes)

fsp_err_t	R_IICA_SLAVE_CallbackSet (i2c_slave_ctrl_t const p_api_ctrl, void(p_callback)(i2c_slave_callback_args_t ), void const const p_context, i2c_slave_callback_args_t *const p_callback_memory)

fsp_err_t	R_IICA_SLAVE_Close (i2c_slave_ctrl_t *const p_api_ctrl)

Detailed Description

Driver for the IICA peripheral on RA MCUs. This module implements the I2C Slave Interface.

Overview

Features

Supports multiple transmission rates
- Standard Mode Support with up to 100-kHz transaction rate.
- Fast Mode Support with up to 400-kHz transaction rate.
- Fast Mode Plus Support with up to 1-MHz transaction rate.
Reads data written by master device.
Write data which is read by master device.
Clock stretching is supported and can be implemented via callbacks.
Provides Transmission/Reception transaction size in the callback.
IICA Slave can notify the following events via callbacks: Transmission/Reception Request, Transmission/Reception Request for more data, Transmission/Reception Completion, Error Condition.

Configuration

Build Time Configurations for r_iica_slave

The following build time configurations are defined in fsp_cfg/r_iica_slave_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.
10-bit slave addressing	Enabled Disabled	Disabled	If enabled, the driver will support 10-bit slave addressing mode.
General call addressing	Enabled Disabled	Disabled	If enabled, the driver will support general call slave addressing mode along with the non-general call slave addressing mode.

Configurations for Connectivity > IICA Slave (r_iica_slave)

This module can be added to the Stacks tab via New Stack > Connectivity > IICA Slave (r_iica_slave).

Configuration	Options	Default	Description
Name	Name must be a valid C symbol	g_iica_slave0	Module name.
Rate	Standard Fast-mode Fast-mode plus	Standard	Select the transfer rate. If the requested transfer rate cannot be achieved, the settings with the largest possible transfer rate that is less than or equal to the requested transfer rate are used. The theoretical calculated transfer rate is printed in a comment in the generated iica_slave_extended_cfg_t structure.
Internal Reference Clock	PCLKB / 1 PCLKB / 2	PCLKB / 1	Select the internal reference clock for IICA slave.
Signal Rising Time (us)	Must be a valid value	0	Set the SDA and SCL signal rising time in micro-seconds.
Signal Falling Time (us)	Must be a valid value	0	Set the SDA and SCL signal falling time in micro-seconds.
Duty Cycle (%)	Value must be an integer between 0 and 100	53	Set SCL high duty cycle.
Digital Filter	Enabled Disabled	Disabled	Configure digital filter.
Slave Address	Value must be non-negative	0x08	Specify the slave address.
Callback	Name must be a valid C symbol	iica_slave_callback	A user callback function must be provided. This will be called from the interrupt service routine (ISR) to report IICA Slave transaction events and status.
IICA0 communication interrupt priority	MCU Specific Options		Select end of IICA0 communication interrupt priority.
SCLA Pin	Disabled P100 P110 P212 P914	Disabled	Specify SCLA pin setting for the MCU.
SDAA Pin	Disabled P101 P109 P213 P913	Disabled	Specify SDAA pin setting for the MCU.

Clock Configuration

The IICA peripheral module uses the PCLKB as its clock source. The actual I2C transfer rate will be calculated and set by the tooling depending on the selected transfer rate. If the PCLKB is configured in such a manner that the selected transfer rate cannot be achieved, an error will be returned.

Pin Configuration

The IICA peripheral module uses pins on the MCU to communicate to external devices. I/O pins must be selected and configured as required by the external device. An IICA channel would consist of two pins - SDAA and SCLA for data/address and clock respectively.

Usage Notes

Interrupt Configuration

IICA0 communication interrupt must be enabled in the properties of the selected device.
Note
: During master-write slave-read type of operations if the slave device requires to perform clock stretching after the last data byte is received.

: To support clock stretching (Holding SCL low after the falling edge of the 9th clock cycle), 'Clock Stretching' configuration must be enabled.

Callback

A callback function must be provided which will be invoked for the cases below:
- An I2C Master initiates a transmission or reception: I2C_SLAVE_EVENT_TX_REQUEST; I2C_SLAVE_EVENT_RX_REQUEST
- A Transmission or reception has been completed: I2C_SLAVE_EVENT_TX_COMPLETE; I2C_SLAVE_EVENT_RX_COMPLETE
- An I2C Master is requesting to read or write more data: I2C_SLAVE_EVENT_TX_MORE_REQUEST; I2C_SLAVE_EVENT_RX_MORE_REQUEST
- Error conditions: I2C_SLAVE_EVENT_ABORTED
The callback arguments will contain information about the transaction status/events, bytes transferred and a pointer to the user defined context.
Clock stretching is enabled by the use of callbacks. This means that the IICA slave can hold the clock line SCL LOW to force the I2C Master into a wait state.
The table below shows I2C Slave event handling expected in user code:

IICA Slave Callback Event	IICA Slave API expected to be called
I2C_SLAVE_EVENT_ABORTED	Handle event based on application
I2C_SLAVE_EVENT_RX_COMPLETE	Handle event based on application
I2C_SLAVE_EVENT_TX_COMPLETE	Handle event based on application
I2C_SLAVE_EVENT_RX_REQUEST	R_IICA_SLAVE_Read API. If the slave is a Write Only device call this API with 0 bytes to send a NACK to the master.
I2C_SLAVE_EVENT_TX_REQUEST	R_IICA_SLAVE_Write API
I2C_SLAVE_EVENT_RX_MORE_REQUEST	R_IICA_SLAVE_Read API. If the slave cannot read any more data call this API with 0 bytes to send a NACK to the master.
I2C_SLAVE_EVENT_TX_MORE_REQUEST	R_IICA_SLAVE_Write API

IICA Slave Rate Calculation

The RA Configuration editor calculates the internal baud-rate setting based on the configured transfer rate. The closest possible baud-rate that can be achieved (less than or equal to the requested rate) at the current PCLKB settings is calculated and used.

Limitations

DTC doesn't support IICA
Extension code is not supported
Please configure SDAA and SCLA pins in the IICA module. IICA pins must be set after IICA is enabled.

Examples

Basic Example

This is a basic example of minimal use of the R_IICA_SLAVE in an application. This example shows how this driver can be used for basic read and write operations.

sau_i2c_instance_ctrl_t g_i2c_master_ctrl;
i2c_master_cfg_t        g_i2c_master_cfg =
{
    .channel       = I2C_MASTER_CHANNEL_20,
    .rate          = I2C_MASTER_RATE_STANDARD,
    .slave         = I2C_7BIT_ADDR_IIC_SLAVE,
    .p_callback    = iica_master_callback, // Callback
    .p_context     = &g_i2c_master_ctrl,
    .p_transfer_tx = NULL,
    .p_transfer_rx = NULL,
    .p_extend      = &g_iic_master_cfg_extend_standard_mode
};
iica_slave_instance_ctrl_t g_i2c_slave_ctrl;
i2c_slave_cfg_t            g_i2c_slave_cfg =
{
    .channel    = I2C_SLAVE_CHANNEL_0,
    .rate       = I2C_SLAVE_RATE_STANDARD,
    .slave      = I2C_7BIT_ADDR_IIC_SLAVE,
    .p_callback = iica_slave_callback, // Callback
    .p_context  = &g_i2c_slave_ctrl,
    .p_extend   = &g_iic_slave_cfg_extend_standard_mode
};
void iica_master_callback (i2c_master_callback_args_t * p_args)
{
    g_i2c_master_callback_event = p_args->event;
}
void iica_slave_callback (i2c_slave_callback_args_t * p_args)
{
    g_i2c_slave_callback_event = p_args->event;
    if ((p_args->event == I2C_SLAVE_EVENT_RX_COMPLETE) || (p_args->event == I2C_SLAVE_EVENT_TX_COMPLETE))
    {
        /* Transaction Successful */
    }
    else if ((p_args->event == I2C_SLAVE_EVENT_RX_REQUEST) || (p_args->event == I2C_SLAVE_EVENT_RX_MORE_REQUEST))
    {
        /* Read from Master */
        err = R_IICA_SLAVE_Read(&g_i2c_slave_ctrl, g_i2c_slave_buffer, g_slave_transfer_length);
        assert(FSP_SUCCESS == err);
    }
    else if ((p_args->event == I2C_SLAVE_EVENT_TX_REQUEST) || (p_args->event == I2C_SLAVE_EVENT_TX_MORE_REQUEST))
    {
        /* Write to master */
        err = R_IICA_SLAVE_Write(&g_i2c_slave_ctrl, g_i2c_slave_buffer, g_slave_transfer_length);
        assert(FSP_SUCCESS == err);
    }
    else
    {
        /* Error Event - reported through g_i2c_slave_callback_event */
    }
}
void basic_example (void)
{
    uint32_t i;
    uint32_t timeout_ms = I2C_TRANSACTION_BUSY_DELAY;
    g_slave_transfer_length = I2C_BUFFER_SIZE_BYTES;
    /* Initialize the IIC Slave module */
    err = R_IICA_SLAVE_Open(&g_i2c_slave_ctrl, &g_i2c_slave_cfg);
    /* Handle any errors. This function should be defined by the user. */
    assert(FSP_SUCCESS == err);
    /* Initialize the IIC Master module */
    err = R_SAU_I2C_Open(&g_i2c_master_ctrl, &g_i2c_master_cfg);
    assert(FSP_SUCCESS == err);
    /* Write some data to the transmit buffer */
    for (i = 0; i < I2C_BUFFER_SIZE_BYTES; i++)
    {
        g_i2c_master_tx_buffer[i] = (uint8_t) i;
    }
    /* Send data to I2C slave */
    g_i2c_master_callback_event = I2C_MASTER_EVENT_ABORTED;
    g_i2c_slave_callback_event  = I2C_SLAVE_EVENT_ABORTED;
    err = R_SAU_I2C_Write(&g_i2c_master_ctrl, &g_i2c_master_tx_buffer[0], I2C_BUFFER_SIZE_BYTES, false);
    assert(FSP_SUCCESS == err);
    /* Since there is nothing else to do, block until Callback triggers
     * The Slave Callback will call the R_IICA_SLAVE_Read API to service the Master Write Request.
     */
    while ((I2C_MASTER_EVENT_TX_COMPLETE != g_i2c_master_callback_event ||
            I2C_SLAVE_EVENT_RX_COMPLETE != g_i2c_slave_callback_event) && timeout_ms)
    {
        R_BSP_SoftwareDelay(1U, BSP_DELAY_UNITS_MILLISECONDS);
        timeout_ms--;
    }
    if ((I2C_MASTER_EVENT_ABORTED == g_i2c_master_callback_event) ||
        (I2C_SLAVE_EVENT_ABORTED == g_i2c_slave_callback_event))
    {
        __BKPT(0);
    }
    /* Read data back from the I2C slave */
    g_i2c_master_callback_event = I2C_MASTER_EVENT_ABORTED;
    g_i2c_slave_callback_event  = I2C_SLAVE_EVENT_ABORTED;
    timeout_ms = I2C_TRANSACTION_BUSY_DELAY;
    err = R_SAU_I2C_Read(&g_i2c_master_ctrl, &g_i2c_master_rx_buffer[0], I2C_BUFFER_SIZE_BYTES, false);
    assert(FSP_SUCCESS == err);
    /* Since there is nothing else to do, block until Callback triggers
     * The Slave Callback will call the R_IICA_SLAVE_Write API to service the Master Read Request.
     */
    while ((I2C_MASTER_EVENT_RX_COMPLETE != g_i2c_master_callback_event ||
            I2C_SLAVE_EVENT_TX_COMPLETE != g_i2c_slave_callback_event) && timeout_ms)
    {
        R_BSP_SoftwareDelay(1U, BSP_DELAY_UNITS_MILLISECONDS);
        timeout_ms--;
    }
    if ((I2C_MASTER_EVENT_ABORTED == g_i2c_master_callback_event) ||
        (I2C_SLAVE_EVENT_ABORTED == g_i2c_slave_callback_event))
    {
        __BKPT(0);
    }
    /* Verify the read data */
    if (0U != memcmp(g_i2c_master_tx_buffer, g_i2c_master_rx_buffer, I2C_BUFFER_SIZE_BYTES))
    {
        __BKPT(0);
    }
}

Data Structures
struct	iica_slave_clock_settings_t

struct	iica_slave_pin_settings_t

struct	iica_slave_extended_cfg_t

Data Structure Documentation

◆ iica_slave_clock_settings_t

struct iica_slave_clock_settings_t

IICA clock settings

◆ iica_slave_pin_settings_t

struct iica_slave_pin_settings_t

Configuration settings for IICA pins

Data Fields
bsp_io_port_pin_t	pin	The pin.
uint32_t	cfg	Configuration for the pin.

◆ iica_slave_extended_cfg_t

struct iica_slave_extended_cfg_t

R_IICA_SLAVE extended configuration

Data Fields
iica_slave_clock_settings_t	clock_settings
iica_slave_pin_settings_t	sda_pin_settings	SDAA pin setting.
iica_slave_pin_settings_t	scl_pin_settings	SCLAA pin setting.

Function Documentation

◆ R_IICA_SLAVE_Open()

fsp_err_t R_IICA_SLAVE_Open	(	i2c_slave_ctrl_t *const	p_api_ctrl,
		i2c_slave_cfg_t const *const	p_cfg
	)

Opens the IICA slave device.

Return values

FSP_SUCCESS	IICA slave device opened successfully.
FSP_ERR_ALREADY_OPEN	Module is already open.
FSP_ERR_IP_CHANNEL_NOT_PRESENT	Channel is not available on this MCU.
FSP_ERR_ASSERTION	Parameter check failure due to one or more reasons below: p_api_ctrl or p_cfg is NULL. extended parameter is NULL. Callback parameter is NULL. Invalid IRQ number assigned

◆ R_IICA_SLAVE_Read()

fsp_err_t R_IICA_SLAVE_Read	(	i2c_slave_ctrl_t *const	p_api_ctrl,
		uint8_t *const	p_dest,
		uint32_t const	bytes
	)

Performs a read from the IICA Master device.

This function will fail if there is already an in-progress IICA transfer on the associated channel. Otherwise, the IICA slave read operation will begin. The caller will be notified when the operation has finished by an I2C_SLAVE_EVENT_RX_COMPLETE in the callback. In case the master continues to write more data, an I2C_SLAVE_EVENT_RX_MORE_REQUEST will be issued via callback. In case of errors, an I2C_SLAVE_EVENT_ABORTED will be issued via callback.

Return values

FSP_SUCCESS	Function executed without issue
FSP_ERR_ASSERTION	p_api_ctrl, bytes or p_dest is NULL.
FSP_ERR_IN_USE	Another transfer was in progress.
FSP_ERR_NOT_OPEN	Device is not open.

◆ R_IICA_SLAVE_Write()

fsp_err_t R_IICA_SLAVE_Write	(	i2c_slave_ctrl_t *const	p_api_ctrl,
		uint8_t *const	p_src,
		uint32_t const	bytes
	)

Performs a write to the IICA Master device.

This function will fail if there is already an in-progress IICA transfer on the associated channel. Otherwise, the IICA slave write operation will begin. The caller will be notified when the operation has finished by an I2C_SLAVE_EVENT_TX_COMPLETE in the callback. In case the master continues to read more data, an I2C_SLAVE_EVENT_TX_MORE_REQUEST will be issued via callback. In case of errors, an I2C_SLAVE_EVENT_ABORTED will be issued via callback.

Return values

FSP_SUCCESS	Function executed without issue.
FSP_ERR_ASSERTION	p_api_ctrl or p_src is NULL.
FSP_ERR_IN_USE	Another transfer was in progress.
FSP_ERR_NOT_OPEN	Device is not open.

◆ R_IICA_SLAVE_CallbackSet()

fsp_err_t R_IICA_SLAVE_CallbackSet	(	i2c_slave_ctrl_t *const	p_api_ctrl,
		void()(i2c_slave_callback_args_t )	p_callback,
		void const *const	p_context,
		i2c_slave_callback_args_t *const	p_callback_memory
	)

Updates the user callback and has option of providing memory for callback structure. Implements i2c_slave_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_IICA_SLAVE_Close()

fsp_err_t R_IICA_SLAVE_Close ( i2c_slave_ctrl_t *const p_api_ctrl )

Closes the IICA device.

Return values

FSP_SUCCESS	Device closed successfully.
FSP_ERR_NOT_OPEN	Device not opened.
FSP_ERR_ASSERTION	p_api_ctrl is NULL.

Functions

Detailed Description

Overview

Features

Configuration

Build Time Configurations for r_iica_slave

Configurations for Connectivity > IICA Slave (r_iica_slave)

Clock Configuration

Pin Configuration

Usage Notes

Interrupt Configuration

Callback

IICA Slave Rate Calculation

Limitations

Examples

Basic Example

Data Structures

Data Structure Documentation

◆ iica_slave_clock_settings_t

◆ iica_slave_pin_settings_t

◆ iica_slave_extended_cfg_t

Function Documentation

◆ R_IICA_SLAVE_Open()

◆ R_IICA_SLAVE_Read()

◆ R_IICA_SLAVE_Write()

◆ R_IICA_SLAVE_CallbackSet()

◆ R_IICA_SLAVE_Close()