Chapter 16 Freescale’s Scalable Controller Area Network (S12MSCANV3)
MC9S12XE-Family Reference Manual Rev. 1.19
Freescale Semiconductor
657
4. Clear INITRQ to leave initialization mode and continue in normal mode
16.5.2
Bus-Off Recovery
The bus-off recovery is user configurable. The bus-off state can either be left automatically or on user
request.
For reasons of backwards compatibility, the MSCAN defaults to automatic recovery after reset. In this
case, the MSCAN will become error active again after counting 128 occurrences of 11 consecutive
recessive bits on the CAN bus (See the Bosch CAN specification for details).
If the MSCAN is configured for user request (BORM set in
Section 16.3.2.2, “MSCAN Control Register
”), the recovery from bus-off starts after both independent events have become true:
•
128 occurrences of 11 consecutive recessive bits on the CAN bus have been monitored
•
BOHOLD in
Section 16.3.2.14, “MSCAN Miscellaneous Register (CANMISC)
has been cleared
by the user
These two events may occur in any order.
Because
of
an
order
from
the
United
States
International
Trade
Commission,
BGA-packaged
product
lines
and
part
numbers
indicated
here
currently
are
not
available
from
Freescale
for
import
or
sale
in
the
United
States
prior
to
September
2010:
S12XE
products
in
208
MAPBGA
packages
