Image forming apparatus and power control method thereof

An image forming apparatus having a plurality of power saving operation modes respectively using operating frequencies having different periods, comprising:

• a volatile memory configured to operate by the operating frequencies and a power;
• and
• a System-On-Chip (SoC) part including an internal memory,
• wherein the SoC part is configured to operate using the volatile memory in a normal mode, copy and use information stored in the volatile memory to the internal memory and lower an operating frequency of the volatile memory in a first power saving mode of the plurality of power saving modes, and lower the power supplied to the volatile memory in a second power saving mode of the plurality of power saving modes, and
• wherein the SoC part comprises
• a central processing unit (CPU);
• the internal memory;
• an interface part to receive an external signal;
• and
• a control part to, when the interface part has no input during a first preset time, copy information stored to the volatile memory to the internal memory and to convert to the first power saving mode to lower an operating frequency of the volatile memory and an operating frequency of the CPU, and when a normal mode switch signal is not input during a second preset time in the first power saving mode, to control the CPU to access the information copied to the internal memory and to convert to the second power saving mode to change the volatile memory to a self-refresh mode.