Intel 87C196CB Manual De Usuario
87C196CB SUPPLEMENT
7-8
Table 7-6. Standard Message Frame
Field
Description
Bit Count
SOF
Start-of-frame. A dominant (0) bit marks the beginning of a message frame.
1
Arbitration
11-bit message identifier.
12
RTR. Remote transmission request. Dominant (0) for data frames; recessive (1)
for remote frames.
for remote frames.
Control
IDE. Identifier extension bit; always dominant (0).
6
r0. Reserved bit; always dominant (0).
DLC. Data length code. A 4-bit code indicating the number of data bytes (0–8).
Data
Data. 1 to 8 bytes for data frames; 0 bytes for remote frames.
0–64
CRC
CRC code. A 15-bit CRC code plus a recessive (1) delimiter bit.
16
Ack
Acknowledgment. A dominant (0) bit sent by nodes receiving the frame plus a
recessive (1) delimiter bit.
recessive (1) delimiter bit.
2
End of frame
7 recessive (1) bits mark the end of a frame.
7
Minimum standard message frame length (bits)
44–108
Table 7-7. Extended Message Frame
Field
Description
Bit Count
SOF
Start-of-frame. A dominant (0) bit marks the beginning of a message frame.
1
Arbitration
11 bits of the 29-bit message identifier.
32
SRR. Substitute remote transmission request; always recessive (1).
IDE. Identifier extension bit; always recessive (1).
18 bits of the 29-bit message identifier.
RTR. Remote transmission request; always recessive (1).
Control
r0. Reserved bit; always dominant (0).
6
r1. Reserved bit; always dominant (0).
DLC. Data length code. A 4-bit code indicating the number of data bytes (0–8).
Data
Data. 1 to 8 bytes for data frames; 0 bytes for remote frames.
0–64
CRC
CRC code. A 15-bit CRC code plus a recessive (1) delimiter bit.
16
Ack
Acknowledgment. A dominant (0) bit sent by nodes receiving the frame plus a
recessive (1) delimiter bit.
recessive (1) delimiter bit.
2
End of frame
7 recessive (1) bits mark the end of a frame.
7
Minimum extended message frame length (bits)
64–128