| 摘要 |
<p>PROBLEM TO BE SOLVED: To increase the updating speed of a display screen while making it possible to stop the transfer of image data as necessary, and also to reduce power consumption, occupancy ratio of system buses, and processing burden of a CPU. SOLUTION: Image data are DMA-transferred by DMA transfer A at a constant cycle to a disk memory through a camera module and a DMA circuit. Therefore, a display device performs display operation based on the image data transferred to the display memory, and the image based on the image data from the camera module is displayed on the display device. When a low voltage detecting circuit detects that the voltage of the battery drops below the reference voltage in this sequence, the circuit activates a low battery detection signal S. Then, an application (1) issues a halt message to another application, and also issues a message to a display driver D to display a warning dialog.</p> |
