mc68hc912bc32 Freescale Semiconductor, Inc, mc68hc912bc32 Datasheet - Page 260

• Manufacturer Part Number: mc68hc912bc32
• Description: M68hc12 Microcontrollers
• Manufacturer: Freescale Semiconductor, Inc

RTR — Remote Transmission Request Flag
16.11.3 Data Length Register
The data length register (DLR) keeps the data length field of the CAN frame.
DLC3–DLC0 — Data Length Code Bits
260
msCAN12 Controller
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.
shows the effect of setting the DLC bits.
0 = Data frame
1 = Remote frame
Address: $01xC
Reset:
Read:
Write:
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
6
M68HC12B Family Data Sheet, Rev. 9.1
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
DLC2
2
Count
Data
Byte
0
1
2
3
4
5
6
7
8
DLC1
1
Freescale Semiconductor
DLC0
Bit 0
Table 16-4