13 can message acceptance mask register – Rainbow Electronics AT91CAP9S250A User Manual

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6264A–CAP–21-May-07

AT91CAP9S500A/AT91CAP9S250A

• 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 707

.

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
serviced first.

When several mailboxes try to transmit a message at the same time, the mailbox with the highest priority is serviced first. If
several 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:

39.8.13

CAN Message Acceptance Mask Register

Name:

CAN_MAMx

Access Type:

Read/Write

15

14

13

12

11

10

9

8

MTIMEMARK

15

MTIMEMARK

14

MTIMEMARK

13

MTIMEMARK

12

MTIMEMARK

11

MTIMEMARK

10

MTIMEMARK9

MTIMEMARK8

7

6

5

4

3

2

1

0

MTIMEMARK7

MTIMEMARK6

MTIMEMARK5

MTIMEMARK4

MTIMEMARK3

MTIMEMARK2

MTIMEMARK1

MTIMEMARK0

MOT

Mailbox Object Type

0

0

0

Mailbox is disabled. This prevents receiving or transmitting any messages
with this mailbox.

0

0

1

Reception Mailbox. Mailbox is configured for reception. If a message is
received while the mailbox data register is full, it is discarded.

0

1

0

Reception mailbox with overwrite. Mailbox is configured for reception. If a
message is received while the mailbox is full, it overwrites the previous
message.

0

1

1

Transmit mailbox. Mailbox is configured for transmission.

1

0

0

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.

1

0

1

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.

1

1

X

Reserved

31

30

29

28

27

26

25

24

MIDE

MIDvA

23

22

21

20

19

18

17

16

MIDvA

MIDvB

15

14

13

12

11

10

9

8

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