PURPOSE: To make it unnecessary to connect an external circuit for controlling switching by including a control function for switching the output timing of a video signal in the video display control device.

CONSTITUTION: First and second latch circuits 22, 25 store video display data RGBY outputted from a display control circuit 21 and a transparent(TP) generation circuit 23 generates a 1st TP signal YI based upon the data RGBY. A 3rd latch circuit 24 latches the signal YI and outputs a 2nd TP signal YS. A D/A converter 26 converts the data RGBY into analog video display data RGBY in accordance with conversion mode data A/D outputted from a D-A switching selection circuit 27. A master/slave register 28 inputs mode data M/S and specifies a master or a slave. An YS signal output control circuit 29 controls the output of the signal YS in accordance with the data A/D, M/S. An YI signal I/O control circuit 30 controls the I/O of the signal YI in accordance with the data M/S. A video signal output control circuit 31 inputs the signal YI and controls the outputs of the circuits 26, 29 in accordance with the master/slave operation.