SH7147 Datasheet, PDF (741/1108 Pages) Renesas Technology Corp – 32-Bit RISC Microcomputer SuperH™ RISC engine Family

Section 17 Controller Area Network (RCAN-ET)
Write Error Counter:
TEC/REC can be written in this mode. RCAN-ET can be forced to
become an Error Passive mode by writing a value greater than 127 into
the Error Counters. The value written into TEC is used to write into REC,
so only the same value can be set to these registers. Similarly, RCAN-ET
can be forced to become an Error Warning by writing a value greater than
95 into them.
RCAN-ET needs to be in Halt Mode when writing into TEC/REC
(MCR1 must be "1" when writing to the Error Counter). Furthermore this
test mode needs to be exited prior to leaving Halt mode.Error Passive
Mode: RCAN-ET can be forced to enter Error Passive mode.
Note: the REC will not be modified by implementing this Mode.
However, once running in Error Passive Mode, the REC will increase
normally should errors be received. In this Mode, RCAN-ET will enter
BusOff if TEC reaches 256 (Dec). However when this mode is used
RCAN-ET will not be able to become Error Active. Consequently, at the
end of the Bus Off recovery sequence, RCAN-ET will move to Error
Passive and not to Error Active
When message error occurs, IRR13 is set in all test modes.
17.4.2 Configuration of RCAN-ET
RCAN-ET is considered in configuration mode or after a H/W (Power On Reset)/ S/W (MCR[0])
reset or when in Halt mode. In both conditions RCAN-ET cannot join the CAN Bus activity and
configuration changes have no impact on the traffic on the CAN Bus.
• After a Reset request
The following sequence must be implemented to configure the RCAN-ET after (S/W or H/W)
reset. After reset, all the registers are initialised, therefore, RCAN-ET needs to be configured
before joining the CAN bus activity. Please read the notes carefully.
Rev. 3.00 Oct. 06, 2008 Page 717 of 1080
REJ09B0230-0300