| 摘要 |
PURPOSE:To prevent an erroneous decision result from being inputted to a CPU by providing a control means for inhibiting a supply of a timing signal to a holding circuit in accordance with the contents of a plane register. CONSTITUTION:The title device is provided with a control means 14 for inhibiting a supply of a timing signal to holding circuits 1900-1915 in accordance with the contents of a plane register 11. Even in the case of a hardware which has been converted to an IC to match a system, for instance, of four planes, when only the plane which has been mounted by plane selection data is selected, even if indefinite data is read out from the plane which has not been mounted, a coincidence detection result of its data is not held in the holding circuit. When only data of the plane which has been mounted coincides with a designated color or gradation, a result of decision becomes a coincidence. In such a way, it does not occur that an erroneous decision result is inputted to a CPU. |
