Patent ID: 8799689
Filing Date: 2014-08-05
Classification: G06F,G06K

Abstract:
1. A connectable device connectable to a host device comprising: a first I/O cell that can receive a command signal via a command/response signal line, receive a clock signal via a clock signal line, transmit a response signal via the command/response signal line, and transmit and receive a data signal via data signal lines at any one signal voltage selected from a first voltage and a second voltage which is lower than the first voltage; a first regulator that can output the first voltage and the second voltage; and a connectable device controller that sends, after receiving a command signal requesting switching of the signal voltage from the first voltage to the second voltage from the host device, information indicating whether or not switching of the signal voltage is possible to the host device with the response signal, starts, when switching of the signal voltage is possible, after the clock signal line is set at a ground level by the host device, processing for switching a voltage outputted by the first regulator from the first voltage to the second voltage, applies, when detecting that a voltage other than a ground level is applied to the clock signal line, the second voltage to the command/response signal line, the data signal lines set at the ground level by the connectable device, and starts transmission/reception at the second voltage.