DLN_I2C_MASTER_SET_FREQUENCY Command and Response

The DLN_I2C_MASTER_SET_FREQUENCY command is used to set the clock frequency to synchronize data transfer between master and slave devices.

DLN_I2C_MASTER_SET_FREQUENCY Command

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 typedef struct
 {
    DLN_MSG_HEADER header;
    uint8_t port;
    uint32_t frequency;
 } __PACKED_ATTR DLN_I2C_MASTER_SET_FREQUENCY_CMD;

Parameters:

header

Defines the DLN message header DLN_MSG_HEADER. The header contains several predefined fields and is used to identify and route messages. You must fill the following fields before sending the command:

Field	Description
size	The size of the message. Must be equal to the size of the DLN_I2C_MASTER_SET_FREQUENCY_CMD structure.
msgId	Identifies the message. For the DLN_I2C_MASTER_SET_FREQUENCY command it must be set to 0x0304. You can use the DLN_MSG_ID_I2C_MASTER_SET_FREQUENCY constant.
echoCounter	Can be used to link a command to a response. The response will have the same echoCounter value. This field can be any numerical value from 0 to 0xFFFF (65536).
handle	A handle to the DLN-series adapter.

port

A number of the I2C master port to be configured.

frequency

The frequency value, specified in Hz. A user may specify any value within the range, supported by the DLN-series adapter. This range can be retrieved using the respective function. In case a user enters an incompatible value, it will be approximated as the closest lower frequency value, supported by the adapter.

DLN_I2C_MASTER_SET_FREQUENCY Response

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The adapter sends the DLN_I2C_MASTER_SET_FREQUENCY response after the DLN_I2C_MASTER_SET_FREQUENCY command execution. The response informs a user if the I2C clock frequency has been successfully set.

 typedef struct
 {
    DLN_MSG_HEADER header;
    DLN_RESULT result;
    uint32_t frequency;
 } __PACKED_ATTR DLN_I2C_MASTER_SET_FREQUENCY_RSP;

Parameters:

header

Defines the DLN message header DLN_MSG_HEADER. The response header contains the following fields:

Field	Description
size	The size of the message. It is equal to the size of the DLN_I2C_MASTER_SET_FREQUENCY_RSP structure.
msgId	Contains the message id. For the DLN_I2C_MASTER_SET_FREQUENCY response it is set to 0x0304. The DLN_MSG_ID_I2C_MASTER_SET_FREQUENCY constant can be used to check the message ID.
echoCounter	Links a command to a response. The echoCounter value is copied from the respective command header.
handle	A handle to the DLN-series adapter. You can use the handle field to determine the adapter that have sent the response.

result

Contains the result of the command execution. For DLN_I2C_MASTER_SET_FREQUENCY command DLN-series adapter can return the following result values:

Return Code	Description
DLN_RES_SUCCESS	The clock frequency has been successfully set.

frequency

Contains the actual frequency applied by this command. If the frequency specified in frequency parameter is supported, the actual frequency will equal to it. Otherwise the closest lower value will be applied. If NULL is specified in this parameter, the actual frequency value will not be returned. You can still use the DLN_I2C_MASTER_GET_FREQUENCY command to check the actual frequency.

DLN_I2C_MASTER_SET_FREQUENCY Command and Response