Data processing circuit for temporarily suspending data recording onto a disk

To resume data writing onto a disk, a recording start position detection means ( 19 ) detects a recording start position, and a synchronous setting means ( 20 ) synchronizes recording data with recorded data on a disk so that recording data successive to the recorded data on the disk can be additionally written onto the disk without a break. Data writing onto a disk is suspended until an amount of data equivalent to data writing capacity has been stored in the buffer memory ( 13 ). Data writing is resumed upon detection of the fact that an amount of data equivalent to data writing capacity has been stored in the buffer memory ( 13 ). With the above, power consumption can be reduced during a period when recording capability of a disk recording device exceeds the data transfer speed.