SPRUHM9H October 2014 – May 2024 TMS320F28075 , TMS320F28075-Q1 , TMS320F28076
The message handler stores the message from the CAN Core shift register into the respective message object in the Message RAM. Not only the data bytes, but all arbitration bits and the data length code are stored into the corresponding message object. This makes sure that the data bytes stay associated to the identifier even if arbitration mask registers are used.
The NewDat bit is set to indicate that new data (not yet seen by the CPU) has been received. The CPU must reset the NewDat bit when the CPU reads the message object. If at the time of the reception the NewDat bit was already set, MsgLst is set to indicate that the previous data (not seen by the CPU) is lost. If the RxIE bit is set, the IntPnd bit is set, causing the Interrupt Register to point to this message object.
The TxRqst bit of this message object is reset to prevent the transmission of a remote frame, while the requested data frame has just been received.