A semiconductor device includes a first master and a second master configured to issue requests for accessing to a memory, a first request issuing controller coupled to the first master, and configured to hold the request issued from the first master, a second request issuing controller coupled to the second master, and configured to hold the request issued from the second master, a bus arbiter coupled to the first request issuing controller and the second request issuing controller, a memory controller coupled to the bus arbiter, and including a buffer configured to store the requests issued from the first master and the second master, and a central bus controller configured to grant access rights to the first request issuing controller and the second request issuing controller based on space information of the buffer.