Nations Technologies Inc.
Tel
:
+86-755-86309900
:
info@nationstech.com
Address: Nations Tower, #109 Baoshen Road, Hi-tech Park North.
Nanshan District, Shenzhen, 518057, P.R.China
559
/
631
the hardware will not automatically send the message again.At the end of a transmission operation, the hardware
judge that the transmission request has been completed, and the hardware sets the CAN_TSTS.RQCPM bit. At the
same time, the transmission result can query the CAN_TSTS.TXOKM, CAN_TSTS.ALSTM and
CAN_TSTS.TERRM bits.
Figure 25-7 Send mailbox status
Receiving management
FIFOs with 3 levels depth are used to store received messages. When the application reads the FIFO output mailbox,
it reads the first received message in the FIFO. FIFO is completely managed by hardware, which can simplify the
application program, ensure the consistency of data and reduce the processing time of CPU.
Valid message
According to CAN protocol, when the message is correctly received (no errors are sent up to the last bit of the EOF
field) and passes the identifier filtering, then the message is token as a valid message. Please refer to 25.4.5 Section:
identifier filtering.
PENDING
Ready
TRANSMIT
EMPTY
Highest priority
Non-Highest priority
B
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TXOKM = 1
Transmit succeeded
Start Write Data
to Tx mailbox