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XC161 Derivatives
Peripheral Units (Vol. 2 of 2)
TwinCAN Module
User’s Manual
21-79
V2.2, 2004-01
TwinCAN_X1, V2.1
Note: Changes of bitfield CANPTR for transmission objects are only taken into account
after setting bitfield MSGVAL to ‘10’. This avoids unintentional modification while
the message object is still active by explicitly defining a timing instant for the
update. Bitfield CANPTR for transmission objects can be written while MSGVAL
is ‘01’ or ‘10’, the update always takes place by setting MSGVAL to ‘10’. Changes
of bitfield CANPTR for receive objects are immediately taken into account.
MMC
[10:8]
High
rw
Message Object Mode Control
Bitfield MMC controls the functionality of message
object n.
000
B
Standard message object functionality
010
B
FIFO functionality enabled (base object)
011
B
FIFO functionality enabled (slave object)
100
B
Normal gateway functionality for incoming
frames
101
B
Shared gateway functionality for incoming
frames
others
reserved
0
[7:5],
12
Low
[7:5],
[15:11]
High
–
Reserved; returns ‘0’ if read; should be written with ‘0’.
1) As a result, a message will not be re-transmitted if it has lost arbitration or has been corrupted by an error
frame.
Field
Bits
Type
Description