Required power consumption is reduced for communication between communication
devices connected to a network by an IEEE 1394 bus line. When the network includes
communication in a synchronous communication mode and communication in an asynchronous
communication mode, a power supply for a communication process in the synchronous
communication mode is controlled independently of a power supply for executing
a communication process in the asynchronous communication mode. Similarly, the
power supply for executing the communication process in the asynchronous communication
mode is controlled independently of the power supply for executing the communication
process in the synchronous communication mode.
