DISPLAY CONTROL CIRCUIT AND DISPLAY CONTROL METHOD
A display control circuit in accordance with an exemplary aspect of the present invention is including a display memory that stores display data to be displayed on a display device, the display memory being supplied with electric power through a power-supply terminal, a power-supply unit that connects the power-supply terminal to a power-supply or a ground according to a request, and a control unit that requests the power-supply unit to connect the power-supply terminal to a ground when the display memory enters a standby mode in which no displaying is performed on the display device, and requests the power-supply unit to connect the power-supply terminal to a power supply when a predetermined time has elapsed after the request even if the display memory is in the standby mode.
1 . A display control circuit comprising:
a display memory that stores display data to be displayed on a display device, the display memory being supplied with electric power through a power-supply terminal;
a power-supply unit that connects the power-supply terminal to a power-supply or a ground according to a request; and
a control unit that requests the power-supply unit to connect the power-supply terminal to a ground when the display memory enters a standby mode in which no displaying is performed on the display device, and requests the power-supply unit to connect the power-supply terminal to a power supply when a predetermined time has elapsed after the request even if the display memory is in the standby mode.
2 . The display control circuit according to claim 1 , wherein the display control circuit is a driver circuit connected to a CPU that outputs a signal indicating a standby mode.
3 . The display control circuit according to claim 1 , wherein
the control circuit issues the request by outputting a ground connection signal to the power-supply unit, the ground connection signal indicating whether the power-supply terminal should be connected to the ground or not, and
the power-supply unit makes the connection based on the ground connection signal input from the control unit.
4 . The display control circuit according to claim 1 , wherein
the power-supply unit include a switch that connects the power-supply terminal to the power supply or the ground, and makes the connection by switching the switch.
5 . The display control circuit according to claim 1 , wherein when the standby mode is cancelled, the control unit stores display data in the display memory.
6 . The display control circuit according to claim 1 , wherein the display memory is an SRAM.
7 . The display control circuit according to claim 1 , wherein the predetermined time is a time required to lower a voltage value in a memory cell included in the display memory to a predetermined value.
8 . The display control circuit according to claim 1 , wherein a manufacturing process of the memory is finer than 180 nm.
9 . A display control method to display display data stored in a display memory on a display device, the method comprising:
lowering a voltage value in a memory cell included in the display memory when the display memory enters a standby mode in which no displaying is performed on the display device; and
supplying electric power to the memory cell after the voltage value in the memory cell has been lowered for a predetermined time even if the display memory is in the standby mode.