| 摘要 |
PURPOSE: To attain display control by a microcomputer and to obtain a screen display just after application of power. CONSTITUTION: Video data from a video use A/D converter 6 and audio data from an audio use A/D converter 8 are transferred via a bus 7. A CPU 16 executes a bootstrap program stored in a ROM 15 at application of power. The bootstrap program of the ROM 15 designates a jump destination address by power-on reset, the CPU 16 publicates a jump destination address to execute a set instruction of internal registers 21-24 of a DMA 9. Thus, the DMA 9 is initialized and video data are transferred via the bus 7 even just after application of power and screen display is conducted. The CPU 16 continues bootstrap processing and boots an OS together with the screen display processing at the same time. After the OS is booted up, the CPU 16 transits each function block and the DMA 9 under the management of the OS to control screen display processing. |
