Datasheet
942
SAM9X25 [DATASHEET]
11054E–ATARM–10-Mar-2014
41.9.14 CAN Message Mode Register
Name: CAN_MMRx [x=0..7]
Address: 0xF8000200 (0)[0], 0xF8000220 (0)[1], 0xF8000240 (0)[2], 0xF8000260 (0)[3], 0xF8000280 (0)[4],
0xF80002A0 (0)[5], 0xF80002C0 (0)[6], 0xF80002E0 (0)[7], 0xF8004200 (1)[0], 0xF8004220 (1)[1], 0xF8004240 (1)[2],
0xF8004260 (1)[3], 0xF8004280 (1)[4], 0xF80042A0 (1)[5], 0xF80042C0 (1)[6], 0xF80042E0 (1)[7]
Access: Read-write
This register can only be written if the WPEN bit is cleared in ”CAN Write Protection Mode Register”.
• MTIMEMARK: Mailbox Timemark
This field is active in Time Triggered Mode. Transmit operations are allowed when the internal timer counter reaches the Mailbox
Timemark. See “Transmitting within a Time Window” on page 920.
In Timestamp Mode, MTIMEMARK is set to 0.
• PRIOR: Mailbox Priority
This field has no effect in receive and receive with overwrite modes. In these modes, the mailbox with the lowest number is ser-
viced first.
When several mailboxes try to transmit a message at the same time, the mailbox with the highest priority is serviced first. If sev-
eral mailboxes have the same priority, the mailbox with the lowest number is serviced first (i.e., MBx0 is serviced before MBx 15 if
they have the same priority).
• MOT: Mailbox Object Type
This field allows the user to define the type of the mailbox. All mailboxes are independently configurable. Five different types are
possible for each mailbox:
31 30 29 28 27 26 25 24
–––––
MOT
23 22 21 20 19 18 17 16
–––– PRIOR
15 14 13 12 11 10 9 8
MTIMEMARK
76543210
MTIMEMARK
Value Name Description
0 MB_DISABLED
Mailbox is disabled. This prevents receiving or transmitting any messages with this
mailbox.
1MB_RX
Reception Mailbox. Mailbox is configured for reception. If a message is received
while the mailbox data register is full, it is discarded.
2 MB_RX_OVERWRITE
Reception mailbox with overwrite. Mailbox is configured for reception. If a message
is received while the mailbox is full, it overwrites the previous message.
3 MB_TX Transmit mailbox. Mailbox is configured for transmission.
4 MB_CONSUMER
Consumer Mailbox. Mailbox is configured in reception but behaves as a Transmit
Mailbox, i.e., it sends a remote frame and waits for an answer.
5 MB_PRODUCER
Producer Mailbox. Mailbox is configured in transmission but also behaves like a
reception mailbox, i.e., it waits to receive a Remote Frame before sending its
contents.
6–Reserved