CHAPTER 19 FCAN CONTROLLER (V850/SC3)
User’s Manual U15109EJ3V0UD
652
(b) Error counter
The error counter value is incremented each time an error occurs and is decremented when a transmit or
receive operation ends normally. The count up/count down timing occurs at the first bit of the error
delimiter.
Table 19-29. Error Counter
Status
Transmit Error Counter
(TEC7 to TEC0)
Receive Error Counter
(REC7 to REC0)
Receiving node has detected an error (except for bit
errors that occur in an active error flag or overload flag)
No change
+1
Dominant level is detected following error frame’s
overload flag output by the receiving node
No change
+8
Transmitting node has sent an error flag
[When error counter =
±
0]
<1>
An ACK error was detected in error passive status
and a dominant level was not detected during
error flag output
<2>
A stuff error occurs in the arbitration field
+8
No change
Detection of bit error during output of active error flag or
overload flag (transmitting node with error active status)
+8
No change
Detection of bit error during output of active error flag or
overload flag (receiving node with error active status)
No change
+8
14 consecutive dominant level bits were detected from
the start of each node’s active error flag or overload
flag, followed by detection of eight consecutive
dominant level bits.
Each node has detected eight consecutive dominant
level bits after a passive error flag.
+8
+8
The transmitting node has completed a transmit
operation without any errors (
±
0 if error counter value is
0).
–1
No change
The receiving node has completed a receive operation
without any errors.
No change
• −
1
(1
≤
REC7 to REC0
≤
127)
• ±
0
(REC7 to REC0 = 0)
•
127 is set
(REC7 to REC0 > 127)
(c) Occurrence of bit error during intermission
In this case, an overload frame occurs.
Caution
When an error occurs, error control is performed according to the contents of the
transmitting and receiving error counters as they existed prior to the error’s occurrence.
The error counter value is incremented only after an error flag has been output.