MEGA128CAN Datasheet, PDF (256/413 Pages) ATMEL Corporation – Microcontroller WITH 128K BYTES OF ISP FLASH AND CAN CONTROLLER

CAN MOb Control and DLC
Register - CANCDMOB
Bit
Read/Write
Initial Value
7
6
CONMOB1 CONMOB0
R/W
R/W
-
-
5
RPLV
R/W
-
4
IDE
R/W
-
3
DLC3
R/W
-
2
DLC2
R/W
-
1
DLC1
R/W
-
0
DLC0
R/W
-
CANCDMOB
• Bit 7:6 – CONMOB1:0: Configuration of Message Object
These bits set the communication to be performed (no initial value after RESET).
– 00 - disable.
– 01 - enable transmission.
– 10 - enable reception.
– 11 - enable frame buffer reception
These bits are not cleared once the communication is performed. The user must re-
write the configuration to enable a new communication.
• This operation is necessary to be able to reset the BXOK flag.
• This operation also set the corresponding bit in the CANEN registers.
• Bit 5 – RPLV: Reply Valid
Used in the automatic reply mode after receiving a remote frame.
– 0 - reply not ready.
– 1 - reply ready and valid.
• Bit 4 – IDE: Identifier Extension
IDE bit of the remote or data frame to send.
This bit is updated with the corresponding value of the remote or data frame received.
– 0 - CAN standard rev 2.0 A (identifiers length = 11 bits).
– 1 - CAN standard rev 2.0 B (identifiers length = 29 bits).
• Bit 3:0 – DLC3:0: Data Length Code
Number of Bytes in the data field of the message.
DLC field of the remote or data frame to send. The range of DLC is from 0 up to 8. If
DLC field >8 then effective DLC=8.
This field is updated with the corresponding value of the remote or data frame received.
If the expected DLC differs from the incoming DLC, a DLC warning appears in the CAN-
STMOB register.
256 AT90CAN128
4250E–CAN–12/04