Patent ID: 7889164

Claim:
A mobile terminal device comprising: a first casing half; and a second casing half foldably coupled to said first casing half via a hinge member, wherein said first casing half comprises a host device, wherein said second casing half comprises: a liquid crystal display drive controller interfaced with said host device via a plurality of signal lines; a liquid crystal display whose display operation is controlled by said liquid crystal display drive controller; a sub liquid crystal display drive controller coupled to said liquid crystal display drive controller; and a sub liquid crystal display whose display operation is controlled by said sub liquid crystal display drive controller, wherein said signal lines go through said hinge member, wherein said liquid crystal display drive controller comprises a semiconductor integrated circuit device which includes: external terminals for host interface; a host interface circuit coupled to said external terminals for host interface; a display drive circuit coupled to said host interface circuit; and external terminals for display drive coupled to said display drive circuit, wherein said host interface circuit comprises: a first serial interface circuit for serial data input and output in a differential manner; a parallel interface circuit; and other interface circuits, wherein an interface circuit for use as an interface with a host device is selected according to a host interface mode setting, wherein said host interface circuit, when said first serial interface circuit is selected for use as the interface with said host device, outputs in parallel information for said sub liquid crystal display drive controller, input from said host device via said first serial interface circuit, from said parallel interface circuit to said sub liquid crystal display drive controller and generates interface control signals for the parallel output, and wherein external terminals for host interface assigned to said other interface circuits are used for double duty to output said generated interface control signals to said sub liquid crystal display drive controller.