R01UH0823EJ0100 Rev.1.00
Page 1202 of 1823
Jul 31, 2019
RX23W Group
36. CAN Module (RSCAN)
This flag becomes 1 only when the STSH.REC[7:0] or STSH.TEC[7:0] value exceeds 95 for the first time. Therefore, if
the program writes 0 to this flag with the STSH.REC[7:0] or STSH.TEC [7:0] value remaining over 95, this bit is not set
to 1 until both STSH.REC[7:0] and STSH.TEC[7:0] values become 95 or less and then the STSH.REC[7:0] or
STSH.TEC[7:0] value exceeds 95 again.
This flag becomes 1 when the CAN module becomes error passive state (STSH.REC[7:0] or STSH.TEC[7:0] value >
127). This flag becomes 1 only when the STSH.REC[7:0] or STSH.TEC[7:0] value exceeds 127 for the first time.
Therefore, if the program writes 0 to this flag with the STSH.REC[7:0] or STSH.TEC[7:0] value remaining over 127,
this bit is not set to 1 until both STSH.REC[7:0] and STSH.TEC[7:0] values become 127 or less and then the
STSH.REC[7:0] or STSH.TEC[7:0] value exceeds 127 again.
BOEF Flag (Bus Off Entry Flag)
This flag becomes 1 when the state becomes bus off state (STSH.TEC[7:0] value > 255). This flag also becomes 1 when
the state becomes bus off state with the CTRH.BOM[1:0] bits set to 01b (transition to channel halt mode at bus off
entry).
BORF Flag (Bus Off Recovery Flag)
This flag becomes 1 when 11 consecutive recessive bits have been detected 128 times and the CAN module returns from
the bus off state. However, this flag is not set to 1 if the CAN module returns from the bus off state in any of the
following ways before 11 consecutive recessive bits are detected 128 times.
The CTRL.CHMDC[1:0] bits are set to 01b (channel reset mode).
The CTRL.RTBO bit is set to 1 (forcible return from the bus off state is made).
The CTRH.BOM[1:0] bits are set to 01b (transition to channel halt mode at bus off entry).
The CTRL.CHMDC[1:0] bits are set to 10b (channel halt mode) before 11 consecutive recessive bits are detected
128 times with the CTRH.BOM[1:0] bits set to 11b (transition to channel halt mode upon a request from the
program during bus off).
This flag becomes 1 when the overload frame transmit condition has been detected when performing reception or
transmission.
This flag becomes 1 when 32 consecutive dominant bits have been detected on the CAN bus in channel communication
mode. After that, detection of the bus lock becomes possible again if either of the following conditions is met.
A recessive bit is detected after the BLF flag has been modified from 1 to 0.
The CAN module transitions to channel reset mode and returns to channel communication mode after the BLF flag
has been modified from 1 to 0.
ALF Flag (Arbitration Lost Flag)
This flag becomes 1 when an arbitration lost has been detected.
SERR Flag (Stuff Error Flag)
This flag becomes 1 when a stuff error has been detected.
This flag becomes 1 when a form error has been detected.