RL78/F13, F14    CHAPTER  18   CAN INTERFACE (RS-CAN LITE) 
R01UH0368EJ0210  Rev.2.10      1296  
Dec 10, 2015 
See the CAN specifications (ISO11898-1) if you want to check error occurrence conditions. To clear each flag of this 
register, write 0 by the program. These flags cannot be set to 1 by the program. If any of these flags is set to 1 at the 
timing when the program writes 0 to the flag, the flag is set to 1. Each flag is cleared to 0 in channel reset mode. 
With respect to bits 14 to 8 in the CiERFLL register, if an error is detected with all flags of bits 14 to 8 set to 0 when the 
ERRD bit in the CiCTRH register is set to 0 (only the first error information is displayed), the corresponding flag is set to 1. 
 
•  ADERR Flag 
This flag is set to 1 when a form error has been detected in the ACK delimiter during transmission. 
 
•  B0ERR Flag 
This flag is set to 1 when a recessive bit has been detected though a dominant bit was transmitted. 
 
•  B1ERR Flag 
This flag is set to 1 when a dominant bit has been detected though a recessive bit was transmitted. 
 
•  CERR Flag 
This flag is set to 1 when a CRC error has been detected. 
 
•  AERR Flag 
This flag is set to 1 when an ACK error has been detected. 
 
•  FERR Flag 
This flag is set to 1 when a form error has been detected. 
 
•  SERR Flag 
This flag is set to 1 when a stuff error has been detected. 
 
•  ALF Flag 
This flag is set to 1 when an arbitration lost has been detected. 
 
•  BLF Flag 
This flag is set to 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 bit has been modified from 1 to 0. 
• The CAN module transitions to channel reset mode and returns to channel communication mode after the BLF  
  bit has been modified from 1 to 0. 
 
•  OVLF Flag 
This flag is set to 1 when the overload frame transmit condition has been detected when performing reception or 
transmission.