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DEMO9S08DZ60
Chapter 12 Freescale’s Controller Area Network (S08MSCANV1)
MC9S08DZ60 Series Data Sheet, Rev. 4
248
Freescale Semiconductor
12.4.4
Data Length Register (DLR)
This register keeps the data length field of the CAN frame.
7
6
5
4
3
2
1
0
R
DB7
DB6
DB5
DB4
DB3
DB2
DB1
DB0
W
Reset:
x
x
x
x
x
x
x
x
Figure 12-33. Data Segment Registers (DSR0–DSR7) — Extended Identifier Mapping
Table 12-31. DSR0–DSR7 Register Field Descriptions
Field
Description
7:0
DB[7:0]
Data bits 7:0
7
6
5
4
3
2
1
0
R
DLC3
DLC2
DLC1
DLC0
W
Reset:
x
x
x
x
x
x
x
x
= Unused; always read “x”
Figure 12-34. Data Length Register (DLR) — Extended Identifier Mapping
Table 12-32. DLR Register Field Descriptions
Field
Description
3:0
DLC[3:0]
Data Length Code Bits — The data length code contains the number of bytes (data byte count) of the respective
message. During 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.
message. During 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.
shows the effect of setting the DLC bits.