Chien's searching apparatus

(1) Field of the Invention The present invention attempts to speed up operations by a chien's searching apparatus used in error correction, to thereby miniaturize it and save on its power dissipation. To this end, the apparatus includes a plurality of arithmetic units which share an error-position polynomial calculating unit and an error-numeral polynomial calculating unit as well as selectors and registers, to thereby perform calculation on a plurality of orders in the same cycle. Also, a divider unit is shared in use. If no error is found, the divider unit is stopped.