A semiconductor device includes a first control circuit controlling a first child clock source to receive a clock signal from a parent clock source, a first channel management (CM) circuit transmitting a first clock request to the first control circuit in response to a second clock request received from a first IP block, a second control circuit controlling a second child clock source to receive the clock signal from the parent clock source, a second CM circuit transmitting a third clock request to the second control circuit in response to a fourth clock request received from a second IP block, and a power management unit transmitting a power control command to the first CM circuit and the second CM circuit to control a power state of the first IP block and the second IP block. The first CM circuit and the second exchange signals to maintain a master-slave relationship.