RA Flexible Software Package Documentation  Release v5.2.0

 
I2C Master (r_sci_b_i2c)

Functions

fsp_err_t R_SCI_B_I2C_Open (i2c_master_ctrl_t *const p_api_ctrl, i2c_master_cfg_t const *const p_cfg)
 
fsp_err_t R_SCI_B_I2C_Read (i2c_master_ctrl_t *const p_api_ctrl, uint8_t *const p_dest, uint32_t const bytes, bool const restart)
 
fsp_err_t R_SCI_B_I2C_Write (i2c_master_ctrl_t *const p_api_ctrl, uint8_t *const p_src, uint32_t const bytes, bool const restart)
 
fsp_err_t R_SCI_B_I2C_Abort (i2c_master_ctrl_t *const p_api_ctrl)
 
fsp_err_t R_SCI_B_I2C_SlaveAddressSet (i2c_master_ctrl_t *const p_api_ctrl, uint32_t const slave, i2c_master_addr_mode_t const addr_mode)
 
fsp_err_t R_SCI_B_I2C_CallbackSet (i2c_master_ctrl_t *const p_api_ctrl, void(*p_callback)(i2c_master_callback_args_t *), void const *const p_context, i2c_master_callback_args_t *const p_callback_memory)
 
fsp_err_t R_SCI_B_I2C_StatusGet (i2c_master_ctrl_t *const p_api_ctrl, i2c_master_status_t *p_status)
 
fsp_err_t R_SCI_B_I2C_Close (i2c_master_ctrl_t *const p_api_ctrl)
 

Detailed Description

Driver for the SCI_B peripheral on RA MCUs. This module implements the I2C Master Interface.

Overview

The Simple I2C master on SCI_B HAL module supports transactions with an I2C Slave device. Callbacks must be provided which would be invoked when a transmission or receive has been completed. The callback arguments will contain information about the transaction status, bytes transferred and a pointer to the user defined context.

Features

Configuration

Build Time Configurations for r_sci_b_i2c

The following build time configurations are defined in fsp_cfg/r_sci_b_i2c_cfg.h:

ConfigurationOptionsDefaultDescription
Parameter Checking
  • Default (BSP)
  • Enabled
  • Disabled
Default (BSP) If selected code for parameter checking is included in the build.
DTC on Transmission and Reception
  • Enabled
  • Disabled
Disabled If enabled, DTC instances will be included in the build for both transmission and reception.
10-bit slave addressing
  • Enabled
  • Disabled
Disabled If enabled, the driver will support 10-bit slave addressing mode along with the default 7-bit slave addressing mode.

Configurations for Connectivity > I2C Master (r_sci_b_i2c)

This module can be added to the Stacks tab via New Stack > Connectivity > I2C Master (r_sci_b_i2c). Non-secure callable guard functions can be generated for this module by right clicking the module in the RA Configuration tool and checking the "Non-secure Callable" box.

ConfigurationOptionsDefaultDescription
NameName must be a valid C symbolg_i2c0 Module name.
ChannelValue must be an integer between 0 and 90 Select the SCI channel.
Slave Address Value must be a hex value0x00 Specify the slave address.
Address Mode
  • 7-Bit
  • 10-Bit
7-Bit Select the address mode.
Rate
  • Standard
  • Fast-mode
Standard Select the I2C data 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 and SDA delay are printed in a comment in the generated sci_b_i2c_extended_cfg_t structure.
SDA Output Delay (nano seconds)Must be a valid non-negative integer with maximum configurable value of 300300 Specify the SDA output delay in nanoseconds.
Noise Filter Clock Select
  • The on-chip baud rate generator source clock divided by 1
  • The on-chip baud rate generator source clock divided by 2
  • The on-chip baud rate generator source clock divided by 4
  • The on-chip baud rate generator source clock divided by 8
The on-chip baud rate generator source clock divided by 1 Select the on-chip baud rate generator source clock division setting for the digital noise filter
Clock SourceMCU Specific OptionsSelect the clock source for the SCI I2C module.
Bit Rate Modulation
  • Enable
  • Disable
Enable Enabling bitrate modulation reduces the percent error of the actual bitrate with respect to the requested baud rate. It does this by modulating the number of cycles per clock output pulse, so the clock is no longer a square wave.
CallbackName must be a valid C symbolsci_b_i2c_master_callback A user callback function can be provided. If this callback function is provided, it will be called from the interrupt service routine (ISR).
Interrupt Priority LevelMCU Specific OptionsSelect the interrupt priority level. This is set for TXI, RXI (if used), TEI interrupts.
RX Interrupt Priority Level [Only used when DTC is enabled]MCU Specific OptionsSelect the interrupt priority level. This is set for RXI only when DTC is enabled.

Clock Configuration

The clock for this module is derived from the following peripheral clock for each MCU group:

MCU GroupPeripheral Clock
RA6T2PCLKA
RA8D1PCLKA
RA8M1PCLKA
RA8T1PCLKA

The actual I2C transfer rate can be derived from either SCISPICLK or the peripheral clock (PCLK)1, and will be calculated and set by the tooling depending on the selected transfer rate and the SDA delay. If the selected clock is configured in such a manner that the selected internal rate cannot be achieved, an error will be returned.

Note
1. See Figure 26.2 in the RA6T2 manual for more information.

Pin Configuration

The SCI_B I2C 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 I2C channel would consist of two pins - SDA and SCL for data/address and clock respectively.

Usage Notes

Interrupt Configuration

SCI_B I2C Master Rate Calculation

Enabling DTC with the SCI_B I2C

Multiple Devices on the Bus

Restart

Examples

Basic Example

This is a basic example of minimal use of the r_sci_b_i2c in an application. This example shows how this driver can be used for basic read and write operations.

void basic_example (void)
{
fsp_err_t err;
uint32_t i;
uint32_t timeout_ms = I2C_TRANSACTION_BUSY_DELAY;
/* Initialize the I2C module */
err = R_SCI_B_I2C_Open(&g_i2c_device_ctrl_1, &g_i2c_device_cfg_1);
/* Handle any errors. This function should be defined by the user. */
assert(FSP_SUCCESS == err);
/* Write some data to the transmit buffer */
for (i = 0; i < I2C_BUFFER_SIZE_BYTES; i++)
{
g_i2c_tx_buffer[i] = (uint8_t) i;
}
/* Send data to I2C slave */
g_i2c_callback_event = I2C_MASTER_EVENT_ABORTED;
err = R_SCI_B_I2C_Write(&g_i2c_device_ctrl_1, &g_i2c_tx_buffer[0], I2C_BUFFER_SIZE_BYTES, false);
assert(FSP_SUCCESS == err);
/* Since there is nothing else to do, block until Callback triggers*/
while ((I2C_MASTER_EVENT_TX_COMPLETE != g_i2c_callback_event) && timeout_ms)
{
timeout_ms--;;
}
if (I2C_MASTER_EVENT_ABORTED == g_i2c_callback_event)
{
__BKPT(0);
}
/* Read data back from the I2C slave */
g_i2c_callback_event = I2C_MASTER_EVENT_ABORTED;
timeout_ms = I2C_TRANSACTION_BUSY_DELAY;
err = R_SCI_B_I2C_Read(&g_i2c_device_ctrl_1, &g_i2c_rx_buffer[0], I2C_BUFFER_SIZE_BYTES, false);
assert(FSP_SUCCESS == err);
/* Since there is nothing else to do, block until Callback triggers*/
while ((I2C_MASTER_EVENT_RX_COMPLETE != g_i2c_callback_event) && timeout_ms)
{
timeout_ms--;;
}
if (I2C_MASTER_EVENT_ABORTED == g_i2c_callback_event)
{
__BKPT(0);
}
/* Verify the read data */
if (0U != memcmp(g_i2c_tx_buffer, g_i2c_rx_buffer, I2C_BUFFER_SIZE_BYTES))
{
__BKPT(0);
}
}

Multiple Slave devices on the same channel (bus)

This example demonstrates how a single SCI_B I2C driver can be used to communicate with different slave devices which are on the same channel.

void single_channel_multi_slave (void)
{
fsp_err_t err;
uint32_t timeout_ms = I2C_TRANSACTION_BUSY_DELAY;
err = R_SCI_B_I2C_Open(&g_i2c_device_ctrl_2, &g_i2c_device_cfg_2);
/* Handle any errors. This function should be defined by the user. */
assert(FSP_SUCCESS == err);
/* Clear the recieve buffer */
memset(g_i2c_rx_buffer, '0', I2C_BUFFER_SIZE_BYTES);
/* Read data from I2C slave */
g_i2c_callback_event = I2C_MASTER_EVENT_ABORTED;
err = R_SCI_B_I2C_Read(&g_i2c_device_ctrl_2, &g_i2c_rx_buffer[0], I2C_BUFFER_SIZE_BYTES, false);
assert(FSP_SUCCESS == err);
while ((I2C_MASTER_EVENT_RX_COMPLETE != g_i2c_callback_event) && timeout_ms)
{
timeout_ms--;;
}
if (I2C_MASTER_EVENT_ABORTED == g_i2c_callback_event)
{
__BKPT(0);
}
/* Send data to I2C slave on the same channel */
err = R_SCI_B_I2C_SlaveAddressSet(&g_i2c_device_ctrl_2, I2C_SLAVE_DISPLAY_ADAPTER, I2C_MASTER_ADDR_MODE_7BIT);
assert(FSP_SUCCESS == err);
g_i2c_tx_buffer[0] = (uint8_t) I2C_EXAMPLE_DATA_1;
g_i2c_tx_buffer[1] = (uint8_t) I2C_EXAMPLE_DATA_2;
g_i2c_callback_event = I2C_MASTER_EVENT_ABORTED;
timeout_ms = I2C_TRANSACTION_BUSY_DELAY;
err = R_SCI_B_I2C_Write(&g_i2c_device_ctrl_2, &g_i2c_tx_buffer[0], 2U, false);
assert(FSP_SUCCESS == err);
while ((I2C_MASTER_EVENT_TX_COMPLETE != g_i2c_callback_event) && timeout_ms)
{
timeout_ms--;;
}
if (I2C_MASTER_EVENT_ABORTED == g_i2c_callback_event)
{
__BKPT(0);
}
}

Data Structures

struct  sci_b_i2c_clock_settings_t
 
struct  sci_b_i2c_instance_ctrl_t
 
struct  sci_b_i2c_extended_cfg_t
 

Enumerations

enum  sci_b_i2c_clock_source_t
 

Data Structure Documentation

◆ sci_b_i2c_clock_settings_t

struct sci_b_i2c_clock_settings_t

I2C clock settings

Data Fields
bool bitrate_modulation Bit-rate Modulation Function enable or disable.
uint8_t brr_value Bit rate register settings.
uint8_t clk_divisor_value Clock Select settings.
uint8_t mddr_value Modulation Duty Register settings.
uint8_t cycles_value SDA Delay Output Cycles Select.
uint8_t snfr_value Noise Filter Setting Register value.
sci_b_i2c_clock_source_t clock_source Clock source (PCLK or SCISPICLK)

◆ sci_b_i2c_instance_ctrl_t

struct sci_b_i2c_instance_ctrl_t

I2C control structure. DO NOT INITIALIZE.

◆ sci_b_i2c_extended_cfg_t

struct sci_b_i2c_extended_cfg_t

SCI I2C extended configuration

Data Fields
sci_b_i2c_clock_settings_t clock_settings I2C Clock settings.

Enumeration Type Documentation

◆ sci_b_i2c_clock_source_t

SCI clock source

Function Documentation

◆ R_SCI_B_I2C_Open()

fsp_err_t R_SCI_B_I2C_Open ( i2c_master_ctrl_t *const  p_api_ctrl,
i2c_master_cfg_t const *const  p_cfg 
)

Opens the I2C device.

Return values
FSP_SUCCESSRequested clock rate was set exactly.
FSP_ERR_ALREADY_OPENModule is already open.
FSP_ERR_IP_CHANNEL_NOT_PRESENTChannel is not available on this MCU.
FSP_ERR_ASSERTIONParameter check failure due to one or more reasons below:
  1. p_api_ctrl or p_cfg is NULL.
  2. extended parameter is NULL.
  3. Callback parameter is NULL.
  4. Clock rate requested is greater than 400KHz
  5. Invalid IRQ number assigned

◆ R_SCI_B_I2C_Read()

fsp_err_t R_SCI_B_I2C_Read ( i2c_master_ctrl_t *const  p_api_ctrl,
uint8_t *const  p_dest,
uint32_t const  bytes,
bool const  restart 
)

Performs a read from the I2C device. The caller will be notified when the operation has completed (successfully) by an I2C_MASTER_EVENT_RX_COMPLETE in the callback.

Return values
FSP_SUCCESSFunction executed without issue.
FSP_ERR_ASSERTIONThe parameter p_ctrl, p_dest is NULL, bytes is 0.
FSP_ERR_INVALID_SIZEProvided number of bytes more than uint16_t size (65535) while DTC is used for data transfer.
FSP_ERR_NOT_OPENDevice was not even opened.

◆ R_SCI_B_I2C_Write()

fsp_err_t R_SCI_B_I2C_Write ( i2c_master_ctrl_t *const  p_api_ctrl,
uint8_t *const  p_src,
uint32_t const  bytes,
bool const  restart 
)

Performs a write to the I2C device.

This function will fail if there is already an in-progress I2C transfer on the associated channel. Otherwise, the I2C write operation will begin. When no callback is provided by the user, this function performs a blocking write. Otherwise, the write operation is non-blocking and the caller will be notified when the operation has finished by an I2C_EVENT_TX_COMPLETE in the callback.

Return values
FSP_SUCCESSFunction executed without issue.
FSP_ERR_ASSERTIONp_ctrl, p_src is NULL.
FSP_ERR_INVALID_SIZEProvided number of bytes more than uint16_t size (65535) while DTC is used for data transfer.
FSP_ERR_NOT_OPENDevice was not even opened.

◆ R_SCI_B_I2C_Abort()

fsp_err_t R_SCI_B_I2C_Abort ( i2c_master_ctrl_t *const  p_api_ctrl)

Aborts any in-progress transfer and forces the I2C peripheral into a ready state.

This function will safely terminate any in-progress I2C transfer with the device. If a transfer is aborted, the user will be notified via callback with an abort event. Since the callback is optional, this function will also return a specific error code in this situation.

Return values
FSP_SUCCESSTransaction was aborted without issue.
FSP_ERR_ASSERTIONp_ctrl is NULL.
FSP_ERR_NOT_OPENDevice was not even opened.

◆ R_SCI_B_I2C_SlaveAddressSet()

fsp_err_t R_SCI_B_I2C_SlaveAddressSet ( i2c_master_ctrl_t *const  p_api_ctrl,
uint32_t const  slave,
i2c_master_addr_mode_t const  addr_mode 
)

Sets address and addressing mode of the slave device.

This function is used to set the device address and addressing mode of the slave without reconfiguring the entire bus.

Return values
FSP_SUCCESSAddress of the slave is set correctly.
FSP_ERR_ASSERTIONp_ctrl or address is NULL.
FSP_ERR_NOT_OPENDevice was not even opened.
FSP_ERR_IN_USEAn I2C Transaction is in progress.

◆ R_SCI_B_I2C_CallbackSet()

fsp_err_t R_SCI_B_I2C_CallbackSet ( i2c_master_ctrl_t *const  p_api_ctrl,
void(*)(i2c_master_callback_args_t *)  p_callback,
void const *const  p_context,
i2c_master_callback_args_t *const  p_callback_memory 
)

Updates the user callback and has option of providing memory for callback structure. Implements i2c_master_api_t::callbackSet

Return values
FSP_SUCCESSCallback updated successfully.
FSP_ERR_ASSERTIONA required pointer is NULL.
FSP_ERR_NOT_OPENThe control block has not been opened.
FSP_ERR_NO_CALLBACK_MEMORYp_callback is non-secure and p_callback_memory is either secure or NULL.

◆ R_SCI_B_I2C_StatusGet()

fsp_err_t R_SCI_B_I2C_StatusGet ( i2c_master_ctrl_t *const  p_api_ctrl,
i2c_master_status_t p_status 
)

Provides driver status.

Return values
FSP_SUCCESSStatus stored in p_status.
FSP_ERR_ASSERTIONNULL pointer.

◆ R_SCI_B_I2C_Close()

fsp_err_t R_SCI_B_I2C_Close ( i2c_master_ctrl_t *const  p_api_ctrl)

Closes the I2C device. Power down I2C peripheral.

This function will safely terminate any in-progress I2C transfer with the device. If a transfer is aborted, the user will be notified via callback with an abort event. Since the callback is optional, this function will also return a specific error code in this situation.

Return values
FSP_SUCCESSDevice closed without issue.
FSP_ERR_ASSERTIONThe parameter p_ctrl is NULL.
FSP_ERR_NOT_OPENDevice was not even opened.