Patent ID: 7099704

Claim:
A musical tune playback device that performs musical tune playback in a portable telephone device incorporating a system control means, which does not have musical tune playback functions but provides telephone function processing as a main process, comprising: an interface means; a read/write-enable musical tune data storage means for storing musical tune data containing tone-generation data and tone-generation interval data, which are input thereto via the interface means, wherein the amount of musical tune data to be stored is limited; a read/write-enable waveform data storage means for storing waveform data input thereto via the interface means, wherein the amount of waveform data to be stored is limited; a monitor means for monitoring a vacant capacity of the musical tune data storage means and a vacant capacity of the waveform data storage means; a waveform reproduction means for reproducing and outputting musical tone signals based on the waveform data, which are read from the waveform data storage means; and a performance control means for reading the musical tune data stored in the musical tune data storage means and for controlling the waveform reproduction means to reproduce the musical tone signals based on the read musical tune data, wherein when a prescribed size of a vacant area emerges in the musical tune data storage means, the monitor means communicates a data transfer request to the system control means, which in turn reads from a system storage means the following musical tune data, which are input via the interface means and are stored in the vacant area of the musical tune data storage means, and wherein when a prescribed size of a vacant area emerges in the waveform data storage means, the monitor means communicates a data transfer request to the system control means, which in turn reads from the system storage means the following waveform data, which are input via the interface means and are stored in the vacant area of the waveform data storage means.