Intel 8XC196NT Computer Hardware User Manual


 
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.
Control
IDE. Identifier extension bit; always dominant (0).
6r0. 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.
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).
6r1. 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.
2
End of frame 7 recessive (1) bits mark the end of a frame. 7
Minimum extended message frame length (bits) 64–128