261
7682C–AUTO–04/08
AT90CAN32/64/128
Bit 1 – FERR: Form Error
This flag can generate an interrupt. It must be cleared using a read-modify-write software routine
on the whole CANSTMOB register.
The form error results from one or more violations of the fixed form in the following bit fields:
CRC delimiter.
Acknowledgment delimiter.
EOF
Bit 0 – AERR: Acknowledgment Error
This flag can generate an interrupt. It must be cleared using a read-modify-write software routine
on the whole CANSTMOB register.
No detection of the dominant bit in the acknowledge slot.
19.11.2
CAN MOb Control and DLC Register - 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.
Bit
7
6
5
4
3
2
1
0
CONMOB1 CONMOB0
RPLV
IDE
DLC3
DLC2
DLC1
DLC0
CANCDMOB
Read/Write
R/W
Initial Value
-