| 摘要 |
<p>PURPOSE:To execute a processing accompanied with rewriting of a screen at a high speed even by a background by constituting the processor so that a task to which the background is allocated, uses a graphic controller of an EGC, etc. CONSTITUTION:The information processor 20 is provided with a comparator 64 and a register 50, and an address of a VRAM handled by a processing of a background is written in this register 50 in advance. When the processing of the background tries to execute a processing accompanied with rewriting of an image, an EGC 40 executes a processing of a graphic in the same way as a foreground, and tries to write its result in a VRAM, but the comparator 64 detects a fact of rewriting of a screen by the background, and switches an address bus and a data bus outputted from the EGC 40 so as to be accessible to a main memory 34. As a result, the EGC 40 becomes useable from the processing of the background, as well.</p> |
