SAM3X8C Atmel Corporation, SAM3X8C Datasheet - Page 1225

• Manufacturer Part Number: SAM3X8C
• Manufacturer: Atmel Corporation

Figure 40-12. Receive with Overwrite Mailbox
11057A–ATARM–17-Feb-12
11057A–ATARM–17-Feb-12
Chaining Mailboxes
(CAN_MSRx)
(CAN_MSRx)
CAN_MDHx)
(CAN_MCRx)
(CAN_MDLx
CAN BUS
MRDY
MTCR
MMI
Several mailboxes may be used to receive a buffer split into several messages with the same ID.
In this case, the mailbox with the lowest number is serviced first. In the receive and receive with
overwrite modes, the field PRIOR in the CAN_MMRx register has no effect. If Mailbox 0 and
Mailbox 5 accept messages with the same ID, the first message is received by Mailbox 0 and the
second message is received by Mailbox 5. Mailbox 0 must be configured in Receive Mode (i.e.,
the first message received is considered) and Mailbox 5 must be configured in Receive with
Overwrite Mode. Mailbox 0 cannot be configured in Receive with Overwrite Mode; otherwise, all
messages are accepted by this mailbox and Mailbox 5 is never serviced.
If several mailboxes are chained to receive a buffer split into several messages, all mailboxes
except the last one (with the highest number) must be configured in Receive Mode. The first
message received is handled by the first mailbox, the second one is refused by the first mailbox
and accepted by the second mailbox, the last message is accepted by the last mailbox and
refused by previous ones (see
Message 1
Reading CAN_MDHx & CAN_MDLx
Reading CAN_MSRx
Message 1
Message 2
Figure
40-13).
Message 2
Message 3
Writing CAN_MCRx
Message 3
Message 4
Message ID = CAN_MIDx
Message 4
SAM3X/A
SAM3X/A
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