SPRUIE9D May 2017 – May 2024 DRA74P , DRA75P , DRA76P , DRA77P
If the number of implemented message objects is not sufficient to be used as permanent message objects only, the transmit objects may be managed dynamically. The software can write the whole message (arbitration, control, and data) into the interface register. The bits [23:16] of the command register (DCAN_IF1CMD/DCAN_IF2CMD) can be set to 0xB7 for the transfer of the whole message object content into the message object. Neither Dir, nor TxRqst have to be reset before this operation.
If a previously requested transmission of this message object is not completed but already in progress, it will be continued; however, it will not be repeated if it is disturbed.
To only update the data bytes of a message to be transmitted, bits [23:16] of the command register (DCAN_IF1CMD/ DCAN_IF2CMD) should be set to 0x87.
After the update of the transmit object, the interface register set will contain a copy of the actual contents of the object, including the part that had not been updated.