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CHAPTER 22 CAN CONTROLLER
1
[bit2 - bit0]
LEC
0
1
2
3
4
5
6
7
The LEC field holds a code which indicates the type of the last error to occur on the CAN bus. This field will
be cleared to '0' when a message has been transferred (reception or transmission) without error. The unused
code '7' may be written by the CPU to check for updates.
■ Status Interrupts
A Status Interrupt is generated by bits BOFF and EWARN (Error Interrupt) or by RXOK, TXOK, and LEC
(Status Change Interrupt) assuming 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.
590
Since this bit was last reset by the CPU, a message has been successfully (error free and acknowledged by at least
one other node) transmitted.
Last Error Code (Type of the last error to occur on the CAN bus)
No Error
More than 5 equal bits in a sequence have occurred in a part of a received message
Stuff Error
where this is not allowed.
Form Error
A fixed format part of a received frame has the wrong format.
AckError
The message this CAN Core transmitted was not acknowledged by another node.
During the transmission of a message (with the exception of the arbitration field), the
Bit1Error
device wanted to send a recessive level (bit of logical value '1'), but the monitored bus
value was dominant.
During the transmission of a message (or acknowledge bit or active error flag, or over-
load flag), 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
Bit0Error
each time a sequence of 11 recessive bits has been monitored. This enables the CPU to
monitor the proceeding of the busoff recovery sequence (indicating the bus is not stuck
at dominant level or continuously disturbed).
The CRC check sum was incorrect in the message received, the CRC received for an
CRCError
incoming message does not match with the calculated CRC for the received data.
When the LEC shows the value '7', no CAN bus event was detected since the CPU
unused
wrote this value to the LEC.
MB96300 Super Series Hardware Manual
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