RL78/D1A User's Manual: Hardware - Renesas

Under development
Preliminary document
Specifications in this document are tentative and subject to change.
RL78/D1A CHAPTER 14 CAN CONTROLLER
14.2.4 Error frame
An error frame is output by a node that has detected an error.
Figure 14-15. Error Frame
Error frame
R
D
() ()
Remark D: Dominant = 0
R: Recessive = 1
6 bits 1 to 6 bits 8 bits
Interframe space or overload frame
Error delimiter
Error flag2
Error flag1
Error bit
Table 14-7. Definition Error Frame Fields
No. Name Bit Count Definition
Error flag1 6 Error active node: Outputs 6 dominant-level bits consecutively.
Error passive node: Outputs 6 recessive-level bits consecutively.
If another node outputs a dominant level while one node is outputting a
passive error flag, the passive error flag is not cleared until the same level
is detected 6 bits in a row.
Error flag2 0 to 6 Nodes receiving error flag 1 detect bit stuff errors and issues this error
flag.
Error delimiter 8 Outputs 8 recessive-level bits consecutively.
If a dominant level is detected at the 8th bit, an overload frame is
transmitted from the next bit.
Error bit – The bit at which the error was detected.
Interframe space/overload
frame
The error flag is output from the bit next to the error bit.
In the case of a CRC error, this bit is output following the ACK delimiter.
– An interframe space or overload frame starts from here.5
R01UH0317EJ0004 Rev. 0.04 795
Feb. 22, 2013