HOST APPARATUS, DEVICE, AND COMMUNICATION SYSTEM CONTROL METHOD

摘要

A host apparatus capable of adjusting a current to be consumed by a device in accordance with the power supply performance of the host apparatus. A host apparatus (11) has a plurality of communication ports (P1-P3) to which devices (21-23) are connected. A host controller (14) of the host apparatus (11) communicates with the devices (21-23) to acquire device information including the current consumptions of the devices (21-23). A current supply circuit (15) supplies currents to the devices (21-23) connected to the communication ports (P1-P3). If the sum of the currents consumed by additional devices connected to the communication ports (P1-P3) anew and those consumed by the already connected and recognized devices (21-23) exceeds the current value available from the current supply circuit (15), then an MPU (12) changes the currents supplied from the current supply circuit (15) to the devices (21-23).