
619
Chapter 16
FCAN Controller
User’s Manual U16702EE3V2UD00
(21) CAN message configuration register (CnMCONFm)
The CnMCONFm register is used to specify the type of the message buffer and to set a mask.
Figure 16-44:
CAN Message Configuration Register (CnMCONFm) Format (1/2)
Note:
The “message buffer that has already received a data frame” is a receive message buffer
whose DN bit has been set to 1.
Remark:
A remote frame is received and stored, regardless of the setting of OWS and DN. A remote
frame that satisfies the other conditions (ID matches, RTR = 0, TRQ = 0) is always received
and stored in the corresponding message buffer (interrupt generated, DN flag set,
MDLC[3:0] bits updated, and recorded to the receive history list).
Note:
The RTR bit specifies the type of message frame that is transmitted from a message buffer
defined as a transmit message buffer. Even if a valid remote frame has been received, RTR of
the transmit message buffer that has received the frame remains cleared to 0. Even if a remote
frame whose ID matches has been received from the CAN bus with the RTR bit of the transmit
message buffer set to 1 to transmit a remote frame, that remote frame is not received or stored
(interrupt generated, DN flag set, MDLC[3:0] bits updated, and recorded to the receive history
list).
7
6
5
4
3
2
1
0
Address R/W After reset
CnMCONFm
OWS
RTR
MT2
MT1
MT0
0
0
MA0
see Table
16-16
R/W undefined
OWS
Overwrite control bit
0
The message buffer
Note
that has already received a data frame is not overwritten by a newly
received data frame. The newly received data frame is discarded.
1
The message buffer that has already received a data frame is overwritten by a newly received
data frame.
RTR
Remote frame request bit
Note
0
Transmit a data frame.
1
Transmit a remote frame.
MT2
MT1
MT0
Message buffer type setting bit
0
0
0
Transmit message buffer
0
0
1
Receive message buffer (no mask setting)
0
1
0
Receive message buffer (mask 1 set)
0
1
1
Receive message buffer (mask 2 set)
1
0
0
Receive message buffer (mask 3 set)
1
0
1
Receive message buffer (mask 4 set)
Other than above
Setting prohibited
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