A semiconductor device having a plurality of modules is provided which enables each module to perform properly while managing allowable power for an entire chip through power control based on distributed control. A predetermined power consumption value is defined for each module. The predetermined power consumption value refers to power consumption defined taking into account allowable power values for a plurality of modules. Each module takes and regards a difference between the predetermined power consumption value and an actual power consumption value as extra power and notifies other modules of extra power thereof. To avoid a deadlock, each module is designed to be capable of perform data processing below the predetermined power consumption value without using extra power from another module. When notified of extra power by another module, each module can use for data processing electric power that equals to the predetermined power consumption thereof and the extra power notified thereto.