Patent ID: 8762765

Claim:
An electronic apparatus with which an external apparatus is connected and which performs at least one of inputting and outputting a signal to and from the external apparatus, comprising: a clock section in which a frequency is set and which gives a clock signal having the set frequency; an input-output section which performs an input-output operation including at least one of inputting and outputting the signal according to the clock signal given from the clock section; a frequency detecting section which detects a frequency of the signal given from the external apparatus; and a frequency setting section which determines the frequency of the clock signal based on the frequency detected by the frequency detecting section, and sets the frequency in the clock section, and wherein the clock section comprises: a storing section which stores a plurality of frequencies and rewritably stores one or more frequencies other than the plurality of frequencies; a designating section which one of the frequencies stored in the storing section is designated; and an oscillating section which gives a clock signal having the frequency designated in the designating section, and the electronic apparatus includes a frequency notifying-storing section of which a frequency is notified via a communication line from the external apparatus and which stores the notified frequency in the storing section, wherein the frequency of the frequency notifying-storing section is different from the plurality of frequencies previously stored in the storing section.