Datasheet

V850ES/JG3-H, V850ES/JH3-H CHAPTER 20 CAN CONTROLLER
R01UH0042EJ0500 Rev.5.00 Page 912 of 1513
Aug 12, 2011
Figure 20-17. Recovery from Bus-off State Through Normal Recovery Sequence
»error-passive«
00H
00H ≠ 00H
00H
80H ≤ TEC[7:0] ≤ FFH
BOFF bit
in C0INFO
register
OPMODE[2:0]
in C0CTRL
register
(written by user)
OPMODE[2:0]
in C0CTRL
register
(read by user)
TEC[7:0]
in C0ERC
register
REC[7:0]
in C0ERC
register
TEC > FFH
≠ 00H
≠ 00H
≠ 00H
FFH < TEC [7:0]
»bus-off« »bus-off-recovery-sequence« »error-active«
00H ≤ TEC[7:0] < 80H
00H ≤ REC[7:0] < 80H
00H ≤ REC[7:0] ≤ 80H
<1>
<2>
<3>
Undefined
(b) Forced recovery operation that skips bus-off recovery sequence
The CAN module can be forcibly released from the bus-off state, regardless of the bus state, by skipping the
bus-off recovery sequence. Here is the procedure.
First, the CAN module requests to enter the initialization mode. For the operation and points to be noted at
this time, see 20.3.6 (5) (a) Recovery from bus-off state through normal recovery sequence.
Next, the module requests to enter an operation mode. At the same time, the C0CTRL.CCERC bit must be
set to 1.
As a result, the bus-off recovery sequence defined by the CAN protocol ISO 11898 is skipped, and the module
immediately enters the operation mode. In this case, the module is connected to the CAN bus after it has
monitored 11 consecutive recessive-level bits. For details, refer to the processing in Figure 20-54.
Caution This function is not defined by the CAN protocol ISO 11898. When using this function,
thoroughly evaluate its effect on the network system.