A data store system and a data restoration system that can decrease power consumed in data store-processing or data restoration are provided.A data transfer system includes a function block having store data; a storage section for storing the store data transferred from the function block; a bus having a bit width of a predetermined number of bits where the function block and the storage section are connected; and a controller for sending a store period clock to the function block and the storage section at the data store-processing and sending a restoration period clock to the function block and the storage section at the data restoration. In synchronization with the store period clock, the function block sends store data a predetermined number of bits at a time within the bit width of the bus to the bus and the storage section stores the store data sent in sequence from the function block through the bus. In synchronization with the restoration period clock, and the storage section sends the stored store data as many bits as the bit width of the bus at a time to the bus, and the function block reads the store data a predetermined number of bits at a time from the bus.