XC912BC32CFU8 Motorola Semiconductor Products, XC912BC32CFU8 Datasheet - Page 282

• Manufacturer Part Number: XC912BC32CFU8
• Description: M68HC12B Family Data Sheet
• Manufacturer: Motorola Semiconductor Products

msCAN12 Controller
16.11.3 Data Length Register
Data Sheet
282
RTR — Remote Transmission Request Flag
The data length register (DLR) keeps the data length field of the CAN frame.
DLC3–DLC0 — Data Length Code Bits
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 supports 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.
effect of setting the DLC bits.
Address: $01xC
Reset:
Read:
Write:
0 = Data frame
1 = Remote frame
Note: x is 4, 5, 6, or 7 depending on which buffer, RxFG, Tx0, Tx1, or Tx3, respectively.
Bit 7
DLC3
Figure 16-13. Data Length Register (DLR)
= Unimplemented
0
0
0
0
0
0
0
0
1
msCAN12 Controller
6
Table 16-4. Data Length Codes
Data Length Code
DLC2
0
0
0
0
1
1
1
1
0
5
Undefined out of reset
DLC1
4
0
0
1
1
0
0
1
1
0
DLC3
3
DLC0
0
1
0
1
0
1
0
1
0
M68HC12B Family — Rev. 8.0
DLC2
2
Count
Table 16-4
Data
Byte
0
1
2
3
4
5
6
7
8
DLC1
1
shows the
MOTOROLA
DLC0
Bit 0