Sampling frequency converter

A sampling frequency converter, comprising:

• a buffer that, in response to a write request signal, stores data newly inputted to the buffer, and in response to a read request signal, reads and outputs stored data in order from the oldest one of the stored data;
• an interpolation unit that sequentially receives data, performs an interpolation operation at a generation timing at which a write request signal is generated for calculating interpolated data corresponding to the generation timing of the write request signal from a specified number of the most recently received data up to the generation timing of the write request signal, and supplies the interpolated data to the buffer;
• a writing speed adjusting unit that recurrently generates a write request signal at a time rate determined according to frequency control information, thereby causing the interpolation unit to execute the interpolation operation responsibly to the write request signal, and causing the buffer to store the data outputted from the interpolation unit responsibly to the write request signal;
• a speed correction pointer that increases a pointer value when a write request signal is generated, and decreases the pointer value when a read request signal is generated;
• and
• a frequency control unit that corrects the frequency control information based on the pointer value of the speed correction pointer.