Patent ID: 7685449

Claim:
A communication device for performing bidirectional serial communication by using a clock line and a data line, the communication device comprising: a starting condition detecting unit configured to detect a communication starting condition based on levels of the clock line and the data line and generate, in response to detecting the communication starting condition, a wake up signal for waking up another circuit in the communication device from a standby status; a clock sending/receiving unit connected to the clock line and configured to send/receive a clock signal; and an output control unit configured to fix the clock line at a predetermined level by using the clock sending/receiving unit so as to suspend the bidirectional serial communication after the wake up signal is received from the starting condition detecting unit and until a standby status cancel instruction indicating that the other circuit has woken up from the standby status is received from the other circuit; wherein the bidirectional serial communication is performed with another communication device via the clock line and the data line after the other circuit has woken up.