NUC970 Technical Reference Manual
Publication Release Date: Dec. 15, 2015
- 805 -
Revision V1.30
NUC97
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T
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CHNIC
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NUA
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Error Code
Meanings
0
No Error
1
Stuff Error: More than 5 equal bits in a sequence have occurred in a part of a received message
where this is not allowed.
2
Form Error: A fixed format part of a received frame has the wrong format.
3
AckError: The message this CAN Core transmitted was not acknowledged by another node.
4
Bit1Error: During the transmission of a message (with the exception of the arbitration field), the
device wanted
to send a recessive level (bit of logical value ‘1’), but the monitored bus value was
dominant.
5
Bit0Error: During the transmission of a message (or acknowledge bit, or active error flag, or
overload flag), though the device wanted to send a dominant level (data or identifier bit logical
value ‘0’), but the monitored Bus value was recessive. During busoff recovery, this status is set
each time a sequence of 11 recessive bits has been monitored. This enables the CPU to monitor
the proceedings of the busoff recovery sequence (indicating the bus is not stuck at dominant or
continuously disturbed).
6
CRCError: The CRC check sum was incorrect in the message received, the CRC received for an
incoming message does not match with the calculated CRC for the received data.
7
Unused: When the LEC shows the value ‘7’, no CAN bus event was detected since the CPU wrote
this value to the LEC.
Table 5.24-5 Error Code
Status Interrupts
A Status Interrupt is generated by bits BOff and EWarn (Error Interrupt) or by RxOk, TxOk, and LEC
(Status Change Interrupt) assumed that the corresponding enable bits in the CAN Control Register are
set. A change of bit EPass or a write to RxOk, TxOk, or LEC will never generate a Status Interrupt.
Reading the Status Register will clear the Status Interrupt value (8000h) in the Interrupt Register, if it
is pending.