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13
32180 Group User’s Manual (Rev.1.0)
CAN MODULE
13.7 Transmitting Remote Frames
B'0000 0000
Store the
received data
Lo
st in
CAN
bu
s
arb
itration
or
a CAN
bu
s error
occurred
Clear
the
transmit
reque
st
B'0000 1010
B'1010 0011
Store the received data
Clear the transmit
request
B'0000 0011
B'0000 0001
Finished sending
a remote frame
CPU read
B'1010 0101
B'1010 1000
B'1010 1010
Finished
stor
ing
the
receiv
ed
data
Clear
the
receiv
e
request
Store the received data
Clear the receive request
B'1010 0001
B'1010 0111
B'0000 0111
B'0000 0101
Finished storing
the received data
Finished sending
a remote frame
B'1010 0000
Wait for
received data
B'1010 1011
B'0000 1011
Clear the transmit
request
B'0000 0001
Finished storing
the received data
B'0000 1000
CAN bus error
occurred
Finished storing
the received data
Store the received data
Wait for
received data
Finished sending
a remote frame
Store the received data
Clear the receive request
Finished
stor
ing
the
receiv
ed
data
Cl
ear
the
receiv
e requ
est
Finished
sending
a remote
frame
Figure 13.7.2 Operation of the CAN Message Slot Control Register during Remote Frame Transmission
13.7.3 Reading Out Received Data Frames when Set for Remote Frame Transmission
The following shows the procedure for reading out the data frames that have been received in the slot when it is
set for remote frame transmission.
(1) Clearing the TRFIN (Transmit/Receive Finished) bit
Write H’AE or H’00 to the CAN Message Slot Control Register (C0MSLnCNT, C1MSLnCNT) to clear the
TRFIN bit to "0". After this write, the slot operates as follows:
Values Written to CnMSLnCNT
Slot Operation after Write
H’AE
Operates as a data frame receive slot. Whether overwritten can be verified by ML bit.
H’00
The slot stops transmit/receive operation.
Notes: If message-lost check by the ML bit is needed, write H’AE to clear the TRFIN bit.
If the TRFIN bit was cleared by writing H’AE or H’00, it is possible that new data will be stored in the slot while still
reading out a message from it.
The received data frame cannot be read out by writing H’A0 to the register. If the TRFIN bit is cleared by writing
H’A0, the slot performs remote frame transmit operation.
1
2
3
4
5
6
b7(b15)
(b8)
b0
RM
RR
TR
RL
RA
ML
TRSTAT TRFIN
00000000
Bit arrangement in the CAN Message Slot Control Register