Abstract: In a system including a color liquid crystal panel, a liquid crystal display drive control device for driving the panel, and a microprocessor, the display drive control device of the invention lightens the burden imposed on the microprocessor as well as reduces the power consumption of the system.

Abstract: In a system including a color liquid crystal panel, a liquid crystal display drive control device for driving the panel, and a microprocessor, the display drive control device of the invention lightens the burden imposed on a microprocessor as well as reduces the power consumption of the system.

Abstract: There is provided a display driver control circuit which is just suitable for display drive including display with a small amount of change and display with a large amount of change and can realize saving of chip area and reduction of power consumption and cost. In this display driver control circuit, memory capacity of an internal display memory is set smaller than amount of data of one display picture of a display panel as the drive object, and the display data can be transferred with the system in which externally inputted display data is once stored in the display memory and is then sent of a drive circuit to output a drive signal and with the system in which the display data is sent in direct to the drive circuit by way of no display memory to output a drive signal. Moreover, both transfer methods can be executed on the time division basis.

Abstract: No flicker is displayed on the display screen during display of moving pictures and power consumption can be reduced by adding a high quality moving picture display function. Moreover, the number of times of transfer of moving pictures by comprising a still-picture•text•system•I/O bus•interface and a moving picture interface (external display interface), providing a display operation change register (DM) and a RAM access change register (RM) which are changed selectively depending on display content (display mode) displayed on a display device and displaying the display data on the display device via a picture memory even in the moving picture display mode.

Abstract: The display RAM built into a conventional display control device uses a system in which data are sequentially written word by word, it involves a problem that, if th write speed is to be raised to match the transfer speed of display data from the microprocessor, the power consumption will increase in proportion to the transfer speed. The width (number of bits) of write data to a display RAM in a display control device is set to be an integral multiple of the width of write data supplied from an external microprocessor or the like, and two stages of latch circuits for holding write data equivalent to one row of the display RAM are provided.