Patent ID: 8359073

Claim:
A power transmission control device included in a power transmission device in a contactless power transmission system that transmits power from the power transmission device to a power receiving device by electromagnetically coupling a primary coil to a secondary coil to supply the power to a load of the power receiving device, the power transmission control device comprising: a controller controlling the power transmission control device; a host interface communicating with a power transmission-side host; and a register section accessible from the power transmission-side host via the host interface, the controller shifting into a communication mode that executes communication between the power transmission-side host and a power receiving-side host, when the power transmission-side host writes, via the host interface, a communication request command that requests the communication between the hosts to the register section, as well as the controller transmitting the communication request command to the power receiving device, and wherein the register section including a command register in which a command issued by the power transmission-side host is written and a data register that buffers data; and the controller transmitting, to the power receiving device, an OUT transmission command that requests data transmission from the power transmission-side host to the power receiving-side host when the OUT transmission command is written in the command register; and then, the controller transmitting a data transmission command that directs the data transmission and data to the power receiving device when the data transmission command is written in the command register and the data is written in the data register.