Investigation and Reduction of Fault Sensitivity in the FlexRay Communication Controller Registers

It is now widely believed that FlexRay communication protocol will become the de-facto standard for distributed safety-critical automotive systems. In this paper, the fault sensitivity of the FlexRay communication controller registers are investigated using transient single bit-flip fault injection. To do this, a FlexRay bus network, composed of four nodes, was modeled. A total of 135,600 transient single bit-flip faults were injected to all 408 accessible singlebit and multiple-bit registers of the communication controller in one node. The results showed that among all 408 accessible registers, 30 registers were immediately affected by the injected faults. The results also showed that 26.2% of injected faults caused at least one error. Based on the fault injection results, the TMR and the Hamming code techniques were applied to the most sensitive parts of the FlexRay protocol. These techniques reduced the fault affection to the registers from 26.2% to 10.3% with only 13% hardware overhead.