A semiconductor device may comprise a plurality of chips coupled in a ring structure, and the plurality of chips includes a first chip. Each of the plurality of chips may include a key port receiving or outputting a key to circulate the key through the ring structure. The first chip is configured to be in a standby state until an amount of available token becomes equal to or greater than an amount of required token to perform a specific operation in the first chip, when the first chip has the key.