- Overview
- 1. Introduction
- 2. CAN Communication
- 3. CAN Framing
- 4. CAN Bus Access
- 5. CAN Data Protection
-
6. CAN FD
- Motivation
- Advantages and Consequences
- New Types of Frames
- Details of a CAN FD Frame
- Distinguishing CAN from CAN FD Frames
- Compatibility of CAN and CAN FD Controllers
- Accelerated Transmission
- Indicating too many Errors
- More Data with the same Security
- Changed Rules for Bit Stuffing and CRC Calculation
Length of the Data Field
DLC CAN:
9 possible lengths
The Data Length Code (DLC) had already consisted of four bits under traditional CAN. With this it is possible to describe the nine possible legal lengths of the data field, i.e. 0 to 8 bytes.
DLC CAN FD:
16 possible lengths
Now the DLC's remaining seven values 9 through 15 will be used for CAN FD. However the linear correlation between DLC and the number of bytes is abandoned for DLC > 8. The following table displays the different meanings the DLC has for the size of the data field under CAN and CAN FD:
DLC | Data Field Bytes CAN | Data Field Bytes CAN FD |
---|---|---|
0 | 0 | 0 |
1 | 1 | 1 |
2 | 2 | 2 |
3 | 3 | 3 |
4 | 4 | 4 |
5 | 5 | 5 |
6 | 6 | 6 |
7 | 7 | 7 |
8 | 8 | 8 |
9 | 8 | 12 |
10 | 8 | 16 |
11 | 8 | 20 |
12 | 8 | 24 |
13 | 8 | 32 |
14 | 8 | 48 |
15 | 8 | 64 |
Last modified: Wednesday, 22 September 2021, 4:21 PM