Reading Out Received Data Frames When Set For Remote Frame Transmission - Renesas M32R/ECU Series User Manual

13
Bit arrangement in the CAN Message Slot Control Register
b0 (b8) 1 2 3
TR RR RM RL
0 0 0 0
Finished storing
the received data
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
H'AE
H'00
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.
4 5 6 b7(b15)
RA ML TRSTAT TRFIN
0 0 0 0
B'0000 1000
CAN bus error
occurred
Clear the transmit
request
B'0000 1010
Finished sending
a remote frame
B'0000 0000
Store the received data
Clear the receive request
B'0000 0011
B'0000 0001
Store the received data
Clear the receive request
B'0000 0111
B'0000 0101
Slot Operation after Write
Operates as a data frame receive slot. Whether overwritten can be verified by ML bit.
The slot stops transmit/receive operation.
13.7 Transmitting Remote Frames
B'0000 0000
Store the
received data
B'1010 1000 B'1010 1011
Finished storing
the received data
B'1010 1010
Finished sending
a remote frame
Wait for
received data
B'1010 0000
Store the received data
B'1010 0011
Finished sending
a remote frame
B'1010 0001
Store the received data
B'1010 0111
Finished
sending
Store the received data
a remote
frame
Wait for
received data
B'1010 0101
CPU read
13-89
CAN MODULE
Clear the transmit
request
B'0000 1011
Finished storing
the received data
B'0000 0001
32180 Group User's Manual (Rev.1.0)