US Patent 9990207 Semiconductor device, device, and electronic device

A semiconductor device with improved operating speed is provided. A semiconductor device including a memory circuit has a function of storing a start-up routine in the memory circuit and executing the start-up routine, a function of operating the memory circuit as a buffer memory device after executing the start-up routine, and a function of loading the start-up routine into the memory circuit from outside before the semiconductor device is powered off.