262
7679H–CAN–08/08
AT90CAN32/64/128
The rising of this flag does not disable the MOb (the corresponding ENMOB-bit of CANEN regis-
ters is not cleared). The next matching frame will update the BERR flag.
• Bit 3 – SERR: Stuff Error
This flag can generate an interrupt. It must be cleared using a read-modify-write software routine
on the whole CANSTMOB register.
Detection of more than five consecutive bits with the same polarity. This flag can generate an
interrupt.
The rising of this flag does not disable the MOb (the corresponding ENMOB-bit of CANEN regis-
ters is not cleared). The next matching frame will update the SERR flag.
• Bit 2 – CERR: CRC Error
This flag can generate an interrupt. It must be cleared using a read-modify-write software routine
on the whole CANSTMOB register.
The receiver performs a CRC check on every de-stuffed received message from the start of
frame up to the data field. If this checking does not match with the de-stuffed CRC field, a CRC
error is set.
The rising of this flag does not disable the MOb (the corresponding ENMOB-bit of CANEN regis-
ters is not cleared). The next matching frame will update the CERR flag.
• 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
The rising of this flag does not disable the MOb (the corresponding ENMOB-bit of CANEN regis-
ters is not cleared). The next matching frame will update the FERR flag.
• 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.
The rising of this flag does not disable the MOb (the corresponding ENMOB-bit of CANEN regis-
ters is not cleared). The next matching frame will update the AERR flag.
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).
Bit
7
6
5
4
3
2
1
0
CONMOB1 CONMOB0
RPLV
IDE
DLC3
DLC2
DLC1
DLC0
CANCDMOB
Read/Write
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
Initial Value
-
-
-
-
-
-
-
-
Содержание AVR AT90CAN128
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