I2C Controller Write

R2026b

Write data to I2C peripheral device or I2C peripheral device register

Since R2022a

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  • I2C Controller Write block

Libraries:
STM32 Microcontroller Blockset / STM32F1xx Based Boards
STM32 Microcontroller Blockset / STM32F2xx Based Boards
STM32 Microcontroller Blockset / STM32F3xx Based Boards
STM32 Microcontroller Blockset / STM32F4xx Based Boards
STM32 Microcontroller Blockset / STM32F7xx Based Boards
STM32 Microcontroller Blockset / STM32G0xx Based Boards
STM32 Microcontroller Blockset / STM32G4xx Based Boards
STM32 Microcontroller Blockset / STM32H5xx Based Boards
STM32 Microcontroller Blockset / STM32H7xx Based Boards
STM32 Microcontroller Blockset / STM32H7RSxx Based Boards
STM32 Microcontroller Blockset / STM32L4xx Based Boards
STM32 Microcontroller Blockset / STM32L5xx Based Boards
STM32 Microcontroller Blockset / STM32N6xx Based Boards
STM32 Microcontroller Blockset / STM32U5xx Based Boards
STM32 Microcontroller Blockset / STM32WBxx Based Boards

Description

The I2C Controller Write block writes data to an I2C peripheral device that is connected to the board. Using this block, you can write data to a specific register on the I2C peripheral device. For more information on I2C communication, see Support I2C Communication.

Note

You can run a Simulink® model containing I2C Controller Write block in Connected IO mode on STM32 Processor based boards. For more information, see Communicate with Hardware Using Connected IO.

Examples

Get Started with STMicroelectronics STM32 Processor Based Boards

Get Started with STMicroelectronics STM32 Processor Based Boards

Run a Simulink model on STM32 processor.

Ports

Input

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The port writes data to the I2C device on the board.

Data Types: int8 | uint8 | int16 | uint16 | int32 | uint32 | single | double

Output

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The port outputs 0 for a successful write operation.

Dependencies

To enable this port, select the Output error status parameter.

Data Types: uint8

Parameters

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Specify the I2C module on the board to write data to the I2C peripheral device.

Programmatic Use

Block Parameter: I2CModule

The 2-byte ordering options are:

  • BigEndian - The most significant byte is sent first over the I2C bus.

  • LittleEndian - The least significant byte is sent first over the I2C bus.

Programmatic Use

Block Parameter: PeripheralByteOrder

Select the peripheral address source of I2C controller.

Programmatic Use

Block Parameter: PeripheralAddressVia

Specify the I2C peripheral address to write the data. The I2C peripheral device address is a 7-bit address.

Specify this address as an integer or in hexadecimal format by using hex2dec(), for example, ‘hex2dec(‘61’)’.

Programmatic Use

Block Parameter: PeripheralAddress

When you select this parameter, the block writes data to the I2C peripheral register that you specify in the peripheral register address parameter.

When you clear this parameter, the Send no acknowledgment at the end of the transfer and Remove stop bit at the end of data transfer (Repeated start) parameters are displayed. Using these parameters, you can modify the write operation according to your requirements.

Programmatic Use

Block Parameter: RegisterAddressMode

Specify the I2C peripheral register address to write the data.

Specify this address in 8-bit unsigned integer or in hexadecimal format. To specify the address in 8-bit unsigned integer, use uint8(), for example, ‘uint8(20)’. To specify the address in hexadecimal format, use hex2dec(), for example, ‘hex2dec(‘20’)’.

For more information on register read/write, see I2C Register Read/Write.

Dependencies

This parameter appears only when you select Enable register access address mode parameter.

Programmatic Use

Block Parameter: RegisterAddress

When the parameter is not selected, the block sends a STOP condition. This condition indicates that the block has terminated the data transmission and that the I2C bus is free for any other I2C Controller block to initiate the new read/write operation.

When you select this parameter, the block sends another START condition followed by an address and read/write bit. The block sends any number of start conditions recursively. Such a repeated START condition allows write operations to the peripheral devices without releasing the bus. No other Controller block interrupts the operation.

Dependencies

To enable this parameter, deselect the Enable register access address mode parameter.

Programmatic Use

Block Parameter: RepeatedStart

When you select this parameter, the I2C Controller Read block sends a NACK (Not Acknowledge) bit to the peripheral device with the final byte.

When the peripheral device receives the NACK, it waits for a STOP condition from the I2C Controller block. The controller block generates either a STOP condition to abort the transfer or a repeated START condition to start a new transfer.

When you deselect this parameter, the I2C Controller Read block sends an ACK (Acknowledge) bit to the peripheral device at the end of every byte. The ACK indicates that the I2C Controller Read block is ready to read the next byte from the peripheral device.

Dependencies

To enable this parameter, deselect the Enable register access address mode parameter.

Programmatic Use

Block Parameter: NoAck

When you select this parameter, the block configures an output port. The port on the block is labeled as Status, indicating that the block outputs the status of the write operation at the output port.

The block outputs the status as a uint8 value. Each value corresponds to a data transfer status.

Status valueStatus description
0SUCCESS
1BUSY
2ARBITRATION_LOST
4NO_ACKNOWLEDGE
8I2C_BUS_ERROR

Programmatic Use

Block Parameter: OutputStatus

Extended Capabilities

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C/C++ Code Generation
Generate C and C++ code using Simulink® Coder™.

Version History

Introduced in R2022a

See Also