Freescale Semiconductor, Inc.
MSCAN Controller
RTR — Remote transmission request
This flag reflects the status of the Remote Transmission Request bit
in the CAN frame. In the case of a receive buffer it indicates the status
of the received frame and supports the transmission of an answering
frame in software. In the case of a transmit buffer, this flag defines the
setting of the RTR bit to be sent.
0 = Data frame
1 = Remote frame
17.12.3 Data Length Register (DLR)
This register keeps the data length field of the CAN frame.
DLC3 – DLC0 — Data length code bits
The data length code contains the number of bytes (data byte count)
of the respective message. At the transmission of a remote frame, the
data length code is transmitted as programmed while the number of
transmitted data bytes is always 0. The data byte count ranges from
0 to 8 for a data frame. Table 17-3 shows the effect of setting the DLC
bits.
Table 17-3. Data length codes
Data length code
Data
byte
count
DLC3
DLC2
DLC1
DLC0
0
0
0
0
0
0
0
0
1
0
0
0
0
1
1
1
1
0
0
0
1
1
0
0
1
1
0
0
1
0
1
0
1
0
1
0
0
1
2
3
4
5
6
7
8
Technical Data
MC68HC912DG128 — Rev 3.0
MSCAN Controller
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