FlexRay - Difference with CAN | Cypress Semiconductor
FlexRay - Difference with CAN
Background | Overview | Features | In-car Communication Protocol | Target applications | Data transfer method | Difference with CAN | Internal configuration of a node | Electronic signals | Bus Guardian | Topology | Segment configuration | Protocol | Status transition | Error control |
The following table shows the comparison of major specifications of FlexRay and CAN.
Comparison between FlexRay and CAN
|2||Number of channels per a node||1ch||2ch/1ch (option(1))|
|3||Network topology||Bus-type||Bus-type, Star-type, or Coexisting|
|4||Connected nodes (max)||Depending on the delay time of the bus||Bus-type: 22 nodes Star-type: 22 nodes or 64 nodes during active Coexisting: 64 nodes|
|6||Communication||Event trigger||Time trigger + event trigger|
Over Rode Frame
|10||Bus line lock||Possibly bedominant lock(2)||Babbling Idiot(3) (supported by BG(4))|
|11||Error status transition||Error Active,
Bus off (recoverable by software)
Halt (recoverable by a reset or software command)
|12||Error counter||Fixed status transition counter value||Arbitrary status transition counter value|
|13||Type of errors||Bit Error,
|All errors except a clock synchronization|
|14||Oscillator||Ceramic oscillator or crystal oscillator||Crystal oscillator
(BG(4) is separated from the CC(5) clock)
|15||NW management||By software||By hardware (by BD(6) or BG)|
|16||Network synchronization||Synchronized only by sync_seg||Rate correction and offset correction are available.|
|17||Bus length||40m at 1Mbps||22m
(between nodes, between Active-Star and node, and between Active-Star and Active-Star.)
- 1 option:
- The option means it can be switched by the setting value.
- 2 dominant lock:
- Dominant lock means that Bus is stuck to "0".
- 3 Babbling Idiot:
- Babbling Idiot means that incorrect transfer causing damage occurs.
- 4 BGBG:
- BG stands for bus guardian.
- 5 CC:
- CC stands for communication controller.
- 6 BD:
- BD stands for bus driver.
- Note -
Some parts of this site show only the outlines of the actual FlexRay standards to make them easily understood.