Clock integrated circuit including heterogeneous oscillators and apparatus including the clock integrated circuit

A clock integrated circuit comprising:

• a first-type oscillator;
• a phase locked loop (PLL) circuit configured to output a clock signal generated from the first-type oscillator as a first clock signal;
• a second-type oscillator smaller than the first-type oscillator;
• a division circuit configured to divide a clock signal generated from the second-type oscillator and output the divided clock signal as a second clock signal;
• and
• a calibration circuit configured to adjust a frequency division ratio of the division circuit using the first clock signal.

An apparatus comprising:

• a processor configured to perform a data processing operation;
• an electronic circuit;
• and
• a clock integrated circuit configured to provide a main clock signal in a high frequency band to the processor and a real-time clock signal in a low frequency band to the electronic circuit, wherein the real-time clock signal is used for power on and power off operations of the electronic circuit,
• wherein the clock integrated circuit comprises a crystal oscillator, and is further configured to generate the main clock signal and the real-time clock signal using the crystal oscillator.