Patent ID: 7779195

Claim:
The communication control apparatus for common bus connection devices provided between a plurality of devices to which addresses are allocated and a common bus and controlling an access between each of the plurality of devices and the common bus, the communication control apparatus comprising: an input determination unit configured to recognize an identification signal indicating the beginning and end of a packet for the common bus which is an information unit capable of being transmitted by one transfer operation through the common bus, thereby determining whether or not there is an input from the common bus to a first device; a transmission determination unit configured to determine whether or not there is a transmission of the packet from the first device on the common bus to the common bus; and an access suspend unit configured to determine that a second device on the common bus is performing a packet operation and suspending a clock in each unit in the first device when the input determination unit determines that the address of the packet inputted through the common bus from the second device is not destined for the first device and when the transmission determination unit determines that there is not a transmission request for the packet from the first device.