Display driver control circuit and electronic equipment with display device
View Patent ↗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.
1. A display driver control circuit formed on a semiconductor substrate, the display driver control circuit comprising:
an input interface for receiving externally input display data comprising first display data and second display data;
a first selector coupled to the input interface and having a first output and a second output;
a first register coupled to the first selector to control an operation of the first selector so that the first display data is provided to the first output of the first selector and the second display data is provided to the second output of the first selector;
a display memory coupled to the first output of the first selector to store the first display data provided from the first output of the first selector;
a second selector coupled to the second output of the first selector and coupled to an output of the display memory;
a latch circuit coupled an output of the second selector and which stores data corresponding to one horizontal line of a display panel;
an output driver coupled to the latch circuit and which generates and outputs drive signals of gradation voltages based on the first or the second display data;
a second register that stores a setting value for setting a display position on the display panel for the first display data stored in the display memory; and
a display position control portion coupled to the second register and controlling operations of both the second selector and the latch circuit in accordance with the setting value of the second register so that the first display data read from the display memory and the second display data provided from the first selector can be simultaneously stored in the latch circuit.
2. The display driver control circuit according to claim 1 ,
wherein the first register and the second register are arranged to be loaded from one or more sources external to the display driver control circuit.
3. The display driver control circuit according to claim 1 , wherein the display position control portion comprises:
a display access control circuit that controls the first display data read timing from the display memory in accordance with the setting value of the second register; and
a latch address selector coupled to the latch circuit to select an address of the latch circuit to which the first display data is written.
4. The display driver control circuit according to claim 1 ,
wherein the first display data is still picture data and the second display data is moving picture data.
5. The display driver control circuit according to claim 1 ,
wherein a memory capacity of the display memory is less than a size of the display data for one display picture of the display panel.
6. An electronic apparatus comprising:
a display driver control circuit according to claim 1 ;
a display device driven by the display driver control circuit; and
a system control device providing the first display data to be written into the display memory and setting values of the first and the second registers of the display driver control circuit.
7. The electronic apparatus according to claim 6 , wherein the system control device comprises:
a baseband processor providing the first display data; and
an application processor that providing the second display data.