Can 0 message center 15 mask register 3 (c0m15m3), Can message center movx register descriptions – Maxim Integrated High-Speed Microcontroller Users Guide: Network Microcontroller Supplement User Manual

Page 144

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High-Speed Microcontroller User’s

Guide: Network Microcontroller

Supplement

144

CAN 0 Message Center 15 Mask Register 3 (C0M15M3)

MOVX Address

1

7

6

5

4

3

2

1

0

xxxx0Fh

MASK4

MASK3

MASK2

MASK1

MASK0

0

0

0

CAN MESSAGE CENTER MOVX REGISTER DESCRIPTIONS

CAN 0 Message Center y Arbitration Register 0 (C0MyAR0)

CAN 0 Message Center y Arbitration Register 1 (C0MyAR1)

MASK28–MASK0

CAN message center 15 mask registers 0–3. These registers function as the mask for the standard
(EX/ST = 0) or extended (EX/ST = 1) global identification test (EX/ST = 1) when message ID masking

has been enabled (MEME = 1) for message center 15. These registers can only be modified during a

software initialization (SWINT = 1).

When EX/ST = 1, the 29 bits of the message ID are compared against the 29 bits of the CAN message

center 15 arbitration registers, using the 29 bits of the CAN message center 15 mask registers as mask.

When EX/ST = 0, the 11 bits of the message ID are compared against the most significant 11 bits of the

CAN message center 15 arbitration registers, using the most significant 11 bits of the CAN message

center 15 mask registers as a mask. Any bit in the CAN 0 message center 15 mask registers set to 0

ignores the state of the corresponding bit in the incoming message ID field when performing the test.

Any bit in the CAN message center 15 mask registers set to 1 forces the state of the corresponding bit

in the incoming message ID field and CAN message center arbitration registers 0–3 to match before

considering the incoming message a match.

The 3 least significant bits in the CnM15M3 register are not used and do not perform any comparison

of these bit locations. A read of these bits always returns 0, and writes to these bits are ignored.

Programming all mask registers to 00h effectively disables the message center 15 ID test, accepting all

messages. As such, the message center 15 mask registers act as a “don’t care” following a system

reset.

MOVX Address

1

7

6

5

4

3

2

1

0

xxxxy2h

ID28

ID27

ID26

ID25

ID24

ID23

ID22

ID21

MOVX Address

1

7

6

5

4

3

2

1

0

Xxxxy3h

ID20

ID19

ID18

ID17

ID16

ID15

ID14

ID13

CAN 0 Message Center y Arbitration Register 2 (C0MyAR2)

MOVX Address

1

7

6

5

4

3

2

1

0

Xxxxy4h

ID12

ID11

ID10

ID9

ID8

ID7

ID6

ID5

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