Abstract: A log-memory access circuit includes a log memory that stores a log; a connection-channel switching unit that switches between a first connection channel that connects a first access apparatus for accessing the log memory and the log memory and a second connection channel that connects a second access apparatus for accessing the log memory and the log memory; a switch input unit that inputs a switching instruction; a switch instruction unit that issues an instruction for switching between the first connection channel and the second connection channel to the connection-channel switching unit, in response to the input switching instruction; a first power supply unit that supplies power from-the first access apparatus to the individual units; and a second power supply unit that supplies power from the second access apparatus to the individual units, when the power of the first power supply unit is turned off.