Analysis of simultaneous multi-bit induced by a cosmic ray for onboard memory

Accompanying the development of intelligent onboard equipment using high density memories, the soft-error phenomenon, which is the bit upset induced by a cosmic ray, must be investigated. Especially, the simultaneous multi-bit error (SME) induced by a cosmic ray negligible on earth becomes remarkable in space use. This paper entimates the SME occurrence rate of memory chip by computer simulations and describes the results of the SME experiments using a cyclotron. The computer simulation and experiment results confirm the SME occurrence and show that layout of memory cells is important for the probability of SME occurrence. (author)