Patent attributes
A data transmission method superimposes a spread code onto data in order to synthesize a first signal. The method changes the switching frequency of a switching power supply based on the first signal, transmitting the second signal to a plurality of semiconductor apparatuses (satellite apparatuses) via an output line of the switching power supply. The method changes the DC output voltage level of the second signal on the output line of the switching power supply wherein a satellite apparatus may use the second signal for controlling and instructing the satellite apparatuses to make the satellite apparatus shift, for example, from the stopped state or the sand-by mode to the normal operation mode so that the satellite apparatus may receive the first signal.
