I2C#

sl_i2c_instance_t#

sl_i2c_instance_t

Enumeration to represent I2C instances.

This enumeration defines the different I2C instances available in the system.

sl_i2c_status_t#

sl_i2c_status_t

Enumeration to represent I2C driver status values.

This enumeration defines the various status values that can be returned by the I2C driver.

sl_i2c_transfer_type_t#

sl_i2c_transfer_type_t

Enumeration to represent I2C transfer type.

This enumeration defines the different transfer types that can be used by the I2C driver.

sl_i2c_operating_mode_t#

sl_i2c_operating_mode_t

Enumeration to represent I2C operating modes.

This enumeration defines the different operating modes available for the I2C driver.

sl_i2c_power_modes_t#

sl_i2c_power_modes_t

Enumeration to represent I2C power modes.

This enumeration defines the different power modes available for the I2C driver.

sl_i2c_callback_t#

typedef void(* sl_i2c_callback_t) (sl_i2c_instance_t i2c_instance, uint32_t status) )(sl_i2c_instance_t i2c_instance, uint32_t status)

Callback function type for I2C driver events.

This typedef defines the callback function type that is used by the I2C driver to notify the application of various I2C events.

sl_i2c_driver_init#

sl_i2c_status_t sl_i2c_driver_init (sl_i2c_instance_t i2c_instance, const sl_i2c_config_t * p_user_config)

To initialize the I2C module and configure its parameters.

This function configures the I2C instance with the specified settings, including I2C leader/follower mode, operating mode (bus speed), and transfer type (interrupt or DMA). If DMA is selected as the transfer type, the function will also initialize the DMA module. Additionally, it registers the callback for the I2C instance, clears any pending interrupts, and configures the SDL and SCL pins as per the instance requirements.

Returns

• sl_i2c_status_t Status of the initialization:

  • SL_I2C_SUCCESS - Initialization was successful.

  • SL_I2C_CALLBACK_BUSY - The driver is currently busy and cannot process the request.

  • SL_I2C_INVALID_PARAMETER - One or more parameters are invalid.

sl_i2c_driver_set_follower_address#

sl_i2c_status_t sl_i2c_driver_set_follower_address (sl_i2c_instance_t i2c_instance, uint16_t address)

To configure the follower address of the I2C module.

This API is intended to be used only in follower mode after initializing the I2C instance. It updates the follower address register so that the I2C leader device can initiate transfers with the address that matches the follower device's address register.

• Pre-conditions:

  • sl_i2c_driver_init must be called prior.

  • I2C mode must be set to follower mode.

Returns

• sl_i2c_status_t Status code indicating the result of the operation:

  • SL_I2C_SUCCESS - Operation was successful.

  • SL_I2C_INVALID_PARAMETER - Invalid parameters were provided.

sl_i2c_driver_configure_fifo_threshold#

sl_i2c_status_t sl_i2c_driver_configure_fifo_threshold (sl_i2c_instance_t i2c_instance, uint8_t tx_threshold_value, uint8_t rx_threshold_value)

To configure the TX and RX FIFO threshold levels for the I2C instance.

This API allows you to set the threshold levels for the transmit (TX) and receive (RX) FIFO buffers. The valid range is 0-255, where 0 corresponds to a threshold of 1 byte entry, and 255 corresponds to a threshold of 256 byte entries. Note that the value must not exceed the depth of the hardware buffer. Whenever the buffer reaches the threshold value, the respective interrupt occurs.

• Pre-condition:

  • sl_i2c_driver_init must be called prior.

Returns

• sl_i2c_status_t Status code indicating the result of the operation:

  • SL_I2C_SUCCESS - Operation was successful.

  • SL_I2C_INVALID_PARAMETER - Invalid parameters were provided.

sl_i2c_driver_get_frequency#

sl_i2c_status_t sl_i2c_driver_get_frequency (sl_i2c_instance_t i2c_instance, uint32_t * frequency)

To read the current I2C clock frequency.

This API retrieves the current system core clock frequency in Hz by reading the system core clock frequency.

• Pre-condition:

  • sl_i2c_driver_init must be called prior.

Returns

• sl_i2c_status_t Status code indicating the result of the operation:

  • SL_I2C_SUCCESS - Operation was successful.

  • SL_I2C_INVALID_PARAMETER - Invalid parameters were provided.

sl_i2c_driver_send_data_blocking#

sl_i2c_status_t sl_i2c_driver_send_data_blocking (sl_i2c_instance_t i2c_instance, uint16_t address, uint8_t * tx_buffer, uint32_t tx_len)

To send data in blocking mode.

This API sends data in blocking mode, where it sets the follower address if used for leader mode. The call remains blocked until the last byte is transferred.

• Pre-conditions:

  • sl_i2c_driver_init must be called prior.

  • Transfer type must be set to 'using interrupt'.

  • sl_i2c_driver_set_follower_address (if sending from follower).

  • sl_i2c_driver_configure_fifo_threshold.

Note

• It is recommended to use up to 80,000 bytes maximum transfer length, but this limit may vary depending on the available RAM size.

Returns

• sl_i2c_status_t Status code indicating the result:

  • SL_I2C_SUCCESS - Operation was successful.

  • SL_I2C_INVALID_PARAMETER - Invalid parameters were provided.

sl_i2c_driver_send_data_non_blocking#

sl_i2c_status_t sl_i2c_driver_send_data_non_blocking (sl_i2c_instance_t i2c_instance, uint16_t address, uint32_t * tx_buffer, uint32_t tx_len, sl_i2c_dma_config_t * p_dma_config)

To send data in non-blocking mode using DMA.

This API sends data using DMA in a non-blocking mode. It sets the follower address when used in leader mode, configures the DMA TX and RX channels, registers the DMA callback, and enables the DMA channels. The transfer complete flag SL_I2C_DATA_TRANSFER_COMPLETE is updated after data transfer completion.

• Pre-conditions:

  • sl_i2c_driver_init

  • Here transfer-type should be set as DMA-type

  • sl_i2c_driver_set_follower_address, if used in salve application

Note

• Maximum tx_len values can be 30000 (receives back in around 4 seconds)

• The tx_buffer parameter is of type uint32_t. It is recommended to use 8-bit (0-7 bits) data in the buffer, with the remaining bits filled in by the driver internally.

Returns

• status 0 if successful, else error code as follow

  • SL_I2C_SUCCESS (0x0000) - Success

  • SL_I2C_INVALID_PARAMETER (0x000F) - Parameters are invalid

  • SL_I2C_DMA_TRANSFER_ERROR (0x000E) - DMA parameters are invalid

sl_i2c_driver_receive_data_blocking#

sl_i2c_status_t sl_i2c_driver_receive_data_blocking (sl_i2c_instance_t i2c_instance, uint16_t address, uint8_t * rx_buffer, uint32_t rx_len)

To receive data in blocking mode.

This API receives data in blocking mode, where it sets the follower address if used in leader mode. The call remains blocked until the last byte is received.

• Pre-conditions:

  • sl_i2c_driver_init must be called prior.

  • Transfer type must be set to 'using interrupt'.

  • sl_i2c_driver_set_follower_address (if receiving from follower).

  • sl_i2c_driver_configure_fifo_threshold.

Note

• It is recommended to use up to 80,000 bytes maximum transfer length, but this limit may vary depending on the available RAM size.

Returns

• sl_i2c_status_t Status code indicating the result:

  • SL_I2C_SUCCESS - Operation was successful.

  • SL_I2C_INVALID_PARAMETER - Invalid parameters were provided.

sl_i2c_driver_receive_data_non_blocking#

sl_i2c_status_t sl_i2c_driver_receive_data_non_blocking (sl_i2c_instance_t i2c_instance, uint16_t address, uint8_t * rx_buffer, uint32_t rx_len, sl_i2c_dma_config_t * p_dma_config)

To receive data in non-blocking mode using DMA.

This API receives data using DMA in non-blocking mode. It sets the follower address when used in leader mode, configures DMA RX and TX channels, registers the DMA callback, and enables the DMA channels. The transfer complete flag SL_I2C_DATA_TRANSFER_COMPLETE is updated after data transfer completion.

• Pre-conditions:

  • sl_i2c_driver_init must be called prior.

  • Transfer type must be set to 'using DMA'.

  • sl_i2c_driver_set_follower_address if used in follower application.

Note

• • Maximum rx_len values can be 30000 (receives back in around 4 seconds).

  • The default values cannot be any of the reserved address locations: that is, 0x00 to 0x07, or 0x78 to 0x7f.

Returns

• status 0 if successful, else error code as follow

  • SL_I2C_SUCCESS (0x0000) - Success

  • SL_I2C_INVALID_PARAMETER (0x000F) - Parameters are invalid

  • SL_I2C_DMA_TRANSFER_ERROR (0x000E) - DMA parameters are invalid

sl_i2c_driver_transfer_data#

sl_i2c_status_t sl_i2c_driver_transfer_data (sl_i2c_instance_t i2c_instance, sl_i2c_transfer_config_t const * p_transfer_config, uint16_t address)

To transmit and then receive data from an I2C device in blocking mode.

This API first transmits data and then receives data from an I2C device in blocking mode. It sets the follower address when used in leader mode.

• Pre-conditions:

  • sl_i2c_driver_init must be called prior.

  • Transfer type must be set to 'using interrupt'.

  • sl_i2c_driver_set_follower_address if used in follower application.

Note

• • It is recommended to use up to 80,000 bytes maximum transfer length, but this limit may vary depending on the available RAM size.

  • The default values cannot be any of the reserved address locations: 0x00 to 0x07, or 0x78 to 0x7f.

Returns

• sl_i2c_status_t Status code indicating the result:

  • SL_I2C_SUCCESS - Operation was successful.

  • SL_I2C_INVALID_PARAMETER - Invalid parameters were provided.

sl_i2c_driver_deinit#

sl_i2c_status_t sl_i2c_driver_deinit (sl_i2c_instance_t i2c_instance)

To de-initialize the I2C peripheral and clock.

This API de-initializes the I2C peripheral, disables the peripheral clock, and unregisters the callback.

• Pre-condition:

  • sl_i2c_driver_init must be called prior.

Returns

• sl_i2c_status_t Status code indicating the result:

  • SL_I2C_SUCCESS - Operation was successful.

  • SL_I2C_INVALID_PARAMETER - Invalid parameters were provided.

Note

• When the I2C module is used in combination with other peripherals, refer to the following notes:

  1. When sl_i2c_driver_deinit() is called, it will disable the clock for the peripheral. To power off the peripheral, the power domain (PERI_EFUSE) containing different peripherals (e.g., USART, UART, I2C, SSI Master, SSI Slave, Generic-SPI Master, I2S Master, I2S Slave, Micro-DMA Controller, Config Timer, Random-Number Generator, CRC Accelerator, SIO, QEI, MCPWM, and EFUSE) must be powered down. Use the following API to power down the specific power domain if other peripherals are not being used: sl_si91x_peri_efuse_power_down(power_down).

  2. Some peripherals (ULP Peripherals, UULP Peripherals, GPDMA, and SDIO-SPI) have separate domains that can be powered down independently. For additional details, see the Power Architecture section in the Hardware Reference Manual. The ULP_UART has a separate power domain (ULPSS_PWRGATE_ULP_UART) that can be powered down independently. See the rsi_power_save.h file for all power gate definitions.

sl_si91x_i2c_pin_init#

sl_i2c_status_t sl_si91x_i2c_pin_init (sl_i2c_pin_init_t * pin_init)

To configure the I2C pins.

Configures the SDA and SCL pins and enables internal pull-ups for the SDA and SCL lines of the follower device.

Returns

• sl_i2c_status_t Status code indicating the result:

  • SL_I2C_SUCCESS - Operation was successful.

  • SL_I2C_INVALID_PARAMETER - Invalid parameters were provided.

sl_i2c_driver_leader_reconfig_on_power_mode_change#

sl_i2c_status_t sl_i2c_driver_leader_reconfig_on_power_mode_change (sl_i2c_power_modes_t new_power_mode)

To re-configure the I2C leader device on power mode changes.

Re-configures the I2C leader instance (ULP_I2C) for ULP/HP mode, adjusting the I2C clock frequency required for the I2C operating (speed) mode to run in ULP/HP mode.

• Pre-conditions:

  • sl_i2c_driver_init must be called prior.

  • The instance should be in ULP mode when switching to HP mode.

  • The instance should be in HP mode when switching to ULP mode.

  • The instance used should be the ULP-I2C instance.

Returns

• sl_i2c_status_t Status code indicating the result:

  • SL_I2C_SUCCESS - Success.

  • SL_I2C_INVALID_PARAMETER - Invalid parameters were provided.

sl_i2c_driver_enable_repeated_start#

sl_i2c_status_t sl_i2c_driver_enable_repeated_start (sl_i2c_instance_t i2c_instance, boolean_t enable_rep_start)

To enable or disable repeated start and combined format transfer.

This API should be called by a leader application to enable repeated start before starting data transfer. By enabling this, combined format transfers can be used, allowing the I2C to perform combined write/read operations to the same or different followers without releasing the line, ensuring that the operation is not interrupted.

• Pre-condition:

  • sl_i2c_driver_init must be called prior.

Returns

• sl_i2c_status_t Status code indicating the result:

  • SL_I2C_SUCCESS - Operation was successful.

  • SL_I2C_INVALID_PARAMETER - Invalid parameters were provided.

sl_si91x_i2c_wait_till_i2c_is_idle#

sl_i2c_status_t sl_si91x_i2c_wait_till_i2c_is_idle (sl_i2c_instance_t i2c_instance)

To wait until the I2C bus is idle.

This API polls the activity status bit of the leader and follower to determine if the I2C bus is idle. It can be used for synchronization purposes.

Returns

• sl_i2c_status_t Status code indicating the result:

  • SL_I2C_SUCCESS - Success.

  • SL_I2C_INVALID_PARAMETER - Parameters are invalid.

SL_I2C0_DMA_TX_CHANNEL#

#define SL_I2C0_DMA_TX_CHANNEL

31

I2C Peripheral.

Overview#

I2C standard compliant bus interface with open-drain pins. Configurable as Primary or Secondary. Four speed modes: Standard Mode (100 kbps), Fast Mode (400 kbps), Fast Mode Plus (1 Mbps), and High-Speed Mode (3.4 Mbps). 7 or 10-bit addressing. 7 or 10-bit combined format transfers. Support for clock synchronization and bus clear. Programmable SDA hold time. Integrated transmit and receive buffers with support for DMA. Bulk transmit mode in I2C slave mode. Interrupt-based operation (polled mode also available).

Initialization#

Call init API with the init parameters. Call set follower address API in follower mode. Call set FIFO threshold API. I2C0 DMA TX channel number

SL_I2C0_DMA_RX_CHANNEL#

#define SL_I2C0_DMA_RX_CHANNEL

30

I2C0 DMA RX channel number.

SL_I2C1_DMA_TX_CHANNEL#

#define SL_I2C1_DMA_TX_CHANNEL

3

I2C1 DMA TX channel number.

SL_I2C1_DMA_RX_CHANNEL#

#define SL_I2C1_DMA_RX_CHANNEL

2

I2C1 DMA RX channel number.

SL_ULP_I2C_DMA_TX_CHANNEL#

#define SL_ULP_I2C_DMA_TX_CHANNEL

5

ULP_I2C DMA TX channel number.

SL_ULP_I2C_DMA_RX_CHANNEL#

#define SL_ULP_I2C_DMA_RX_CHANNEL

4

ULP_I2C DMA RX channel number.

SL_I2C2_DMA_TX_CHANNEL#

#define SL_I2C2_DMA_TX_CHANNEL

SL_ULP_I2C_DMA_TX_CHANNEL

ULP_I2C DMA TX channel number for backward compatibility.

SL_I2C2_DMA_RX_CHANNEL#

#define SL_I2C2_DMA_RX_CHANNEL

SL_ULP_I2C_DMA_RX_CHANNEL

ULP_I2C DMA RX channel number for backward compatibility.