Data is read from a recording medium and the reproduced data is deinterleaved and stored to a first memory while input/output to/from the first memory is arbitrated. It is determined whether a predetermined number of data units is stored to the first memory. Based on the result data, it is determined whether transfer of the data stored in first memory to a second memory is permitted. If data transfer is permitted, the reproduced data is transferred from the first memory to the second memory, during which time input/output to/from the second memory is arbitrated. The reproduced data stored to the second memory is then error corrected, and user data contained in the error corrected reproduction data is externally output from the second memory.