Data backup apparatus utilized in an electronic control system and data backup method performed in the data backup apparatus

摘要

A data backup apparatus utilized in an electronic control system comprises :control data storing means having a first memory region and a second memory region for storing pieces of control data in the first memory region and the second memory region;effective region designating means for alternately designating the first memory region and the second memory region of the control data storing means as a reading-out effective region on condition that an electric power is supplied to the effective region designating means;control data renewing means for renewing pieces of control data which are stored in either the first or second memory region not designated as the reading-out effective region by the effective region designating means one by one on condition that the electric power is supplied to the control data renewing means, the first memory region and the second memory region of the control data storing means being alternately designated as the reading-out effective region each time the control data are renewed by the control data renewing means, and the renewal of the control data being incompletely finished to store pieces of incomplete control data in either the first or second memory region not designated as the reading-out effective region in cases where the electric power supplied to the control data renewing means is cut off in the middle of the renewal performed by the control data renewing means; andcontrol data reading-out means for reading out pieces of control data stored in the reading-out effective region which is determined by the effective region designating means.