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Chapter 16
FCAN Controller
User’s Manual U16702EE3V2UD00
16.2.2 Frame
types
The following four types of frames are used in the CAN protocol.
(1)
Bus value
The bus values are divided into dominant and recessive.
•
Dominant level is indicated by logical 0.
•
Recessive level is indicated by logical 1.
•
When a dominant level and a recessive level are transmitted simultaneously, the bus value
becomes dominant level.
16.2.3 Data frame and remote frame
(1)
Data frame
A data frame is composed of seven fields.
Figure 16-3:
Data Frame
Remark:
D: Dominant = 0
R: Recessive = 1
Table 16-2:
Frame Types
Frame Type
Description
Data frame
Frame used to transmit data
Remote frame
Frame used to request a data frame
Error frame
Frame used to report error detection
Overload frame
Frame used to delay the next data frame or remote frame
R
D
Interframe space
End of frame (EOF)
ACK field
CRC field
Data field
Control field
Arbitration field
Start of frame (SOF)
Data frame
<1>
<2>
<3>
<4>
<5>
<6> <7>
<8>
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