A semiconductor device and a mobile terminal are described herein. In one example, a semiconductor device is provided that includes: a power-source part; an interface part; a logic part; and a driving part. In the semiconductor device, the power-source part includes a power-source-cutoff-detection circuit operable to detect a first state in which supply of an external power source is cut off. The logic part includes: a data-cutoff-detection circuit operable to detect a second state in which supply of stream data accompanied by synchronizing signals from outside the semiconductor device is cut off undesirably; and a control circuit operable to perform control for having the driving part cope with the power source cutoff with the power-source-cutoff-detection circuit detecting the first state or the data-cutoff-detection circuit detecting the second state.