FITness Assessment - Hardware Algorithm Safety Validation

Error correction codes (ECC) are important safety methods for digital data to gain control of single event upsets (SEU) in integrated digital circuits. SEU are responsible for single bit flips inside a digital circuit caused by ionizing radiation. This effect does not affect the physical structure of the components but the correctness of data inside flip flops. Consequently, data gets corrupted and the correct program flow gets disturbed. This effect needs to be considered especially for safety-critical systems. In the novel ISO 26262 2nd Edition, the automotive domain suggests controlling SEU effects by algorithms that correct single bit errors and detect double bit errors (SEC-DED). This raises the question what kind of impact double bit error correction (DEC) will have on the overall safety level for LiDAR systems. In this paper we determine the difference between two ECC algorithms from a safety point of view: Hamming's code (SEC-DED) and BCH-code (DEC). For this purpose we developed a novel method for algorithm safety validation and applied it to both algorithms.