1. An information processing apparatus that provides a specific function, the information processing apparatus comprising: a non-volatile function program memory to store a function program for providing the specific function; a main memory; an arithmetic device to read and store the function program from the non-volatile function program memory into the main memory at startup of the information processing apparatus and perform an arithmetic operation based on the function program to execute the function program, wherein when reading and storing the function program from the non-volatile function program memory into the main memory at the startup, the arithmetic device operates at a start frequency set for startup as a clock frequency for accessing the non-volatile function program memory, and wherein after reading and storing the function program from the non-volatile function program memory into the main memory at the start-up, the arithmetic device operates at a frequency lower than the start frequency as the clock frequency for accessing the non-volatile function program memory; a non-volatile update program memory provided separately from the non-volatile function program memory to store an update program for updating the function program, wherein, when the non-volatile update program memory stores the update program, the arithmetic device reads and stores the update program from the non-volatile update program memory into the main memory and writes the update program over the function program stored in the non-volatile function program memory to update the function program, wherein when reading and storing the update program from the non-volatile update program memory into the main memory to update the function program, the arithmetic device operates at an update frequency set for update as a clock frequency for accessing the non-volatile update program memory, and wherein after reading and storing the update program from the non-volatile update program memory into the main memory, the arithmetic device operates at a frequency lower than the update frequency as the clock frequency for accessing the non-volatile update program memory; and an external memory storing the update program connected to the information processing apparatus via a network, wherein, when the external memory stores the update program, the arithmetic device downloads the update program from the external memory to the main memory and writes the update program over the function program stored in the non-volatile function program memory to update the function program.