It is an objective of the present invention to provide a technique, when using fixed-length run-length limit codes based on enumeration, that generates fixed-length channel bit words satisfying maximum run-length limitation using a simple configuration. A channel bit word processor according to the present invention includes an avoidance list that describes a difference between a user bit word satisfying a maximum run-length limitation of run-length limit code and a user bit word not satisfying the maximum run-length limitation. The channel bit word processor, if a user bit word does not satisfy the maximum run-length limitation, generates a channel bit word using a user bit word after the difference is added.