NEC UPD703116 User Manual page 530

<4> Data field
The data field contains the amount of data set by the control field. Up to 8 units of data can be set.
Remark Data units in the data field are each 8 bits long and are ordered MSB first.
(Control field)
R
D
<5> CRC field
The CRC field is a 16-bit field that is used to check for errors in transmit data. It includes a 15-bit CRC
sequence and a 1-bit CRC delimiter.
(Data field, control field)
R
D
• The polynomial P(X) used to generate the 15-bit CRC sequence is expressed as: X
8 7
X + X + X
• Transmitting node: No bit stuffing in start of frame, arbitration field, control field, or data field: The
• Receiving node:
530
CHAPTER 11 FCAN CONTROLLER
Figure 11-14. Data Field
Data
(8 bits)
Figure 11-15. CRC Field
4 3
+ X + 1
transferred CRC sequence is calculated entirely from basic data bits.
The CRC sequence calculated using data bits that exclude the stuffing bits in
the receive data is compared with the CRC sequence in the CRC field. If the
two CRC sequences do not match, the node is passed to an error frame.
User's Manual U14492EJ5V0UD
Data field
Data
(8 bits)
CRC field
CRC sequence
CRC delimiter
(15 bits) (1 bit)
(CRC field)
(ACK field)
15 14
+ X + X
10
+