MC912DG128A Motorola, MC912DG128A Datasheet - Page 293

• Manufacturer Part Number: MC912DG128A
• Description: Microcontrollers
• Manufacturer: Motorola

Data Length
Register (DLR)
Data Segment
Registers (DSRn)
25-mscan12
MOTOROLA
RTR — Remote transmission request
This register keeps the data length field of the CAN frame.
DLC3 – DLC0 — Data length code bits
The eight data segment registers contain the data to be transmitted or
being received. The number of bytes to be transmitted or being received
is determined by the data length code in the corresponding DLR.
This flag reflects the status of the Remote Transmission Request bit
in the CAN frame. In case of a receive buffer it indicates the status of
the received frame and allows to support the transmission of an
answering frame in software. In case of a transmit buffer this flag
defines the setting of the RTR bit to be sent.
The data length code contains the number of bytes (data byte count)
of the respective message. At transmission of a remote frame, the
data length code is transmitted as programmed while the number of
transmitted bytes is always 0. The data byte count ranges from 0 to 8
for a data frame.
0 = Data frame
1 = Remote frame
MSCAN Controller
DLC3
0
0
0
0
0
0
0
0
1
Table 40
Table 40 Data length codes
Data length code
DLC2
0
0
0
0
1
1
1
1
0
shows the effect of setting the DLC bits.
DLC1
0
0
1
1
0
0
1
1
0
Programmer’s Model of Message Storage
DLC0
0
1
0
1
0
1
0
1
0
MC68HC912DT128A Rev 2.0
count
Data
byte
0
1
2
3
4
5
6
7
8
MSCAN Controller
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