PURPOSE: To prevent the registration of redundant information, by controlling the storage to a status career storage circuit when the internal status information at present and just preceding are coincident with each other, and storing the number of coincident times of the internal status information to the status career storage circuit.

CONSTITUTION: A microinstruction readout address circuit 11 instructs the address to read out the microinstruction of the address in a microinstruction word memory 12 and sequentially stores the output address to an address comparison register 32'. The address output of the circuit and the address stored in the register 32' are compared at an address comparison circuit 40, the content of the circuit 11 is sequentially stored in a status career storage circuit 20. Every time when the storage is executed, the address counter 31 revises the content of an address register 30. When the result of comparison is coincident in the circuit 40, the number of times of coincidence is counted at a coincidence counter 41 and the revision of the status career storage data of the internal state can not be executed.