| 摘要 |
<p>PURPOSE:To make an address control easier, to reduce circuitry, to attain the high speed and to reduce cost by maintaining the continuity of the address along a raster scanning direction. CONSTITUTION:The map data of meshes #1 to 4, #6 to 9, #11 to 14, #16 to to 19 and #21 to 24 (total 20 meshes of 4 meshes in an X-direction and 5 meshes in a Y-direction) is written in memories 11 to 15, the writing leading address of the mesh #1 is set to 512 by a raster scanning order. The map data of the mesh #1 is written in a rectangular storage area M 1 which is the leading in the raster scanning order. At the time, an address generation part adds an address 12 at a point of time when the map data corresponding to the leading 32 picture elements (=4 numbers) is written. Thus, the next data is written in an address 528. Therefore, when map data is read from the memories 11 to 15 for a display, the reading can be performed only if a reading address is generated in the same order as the raster scanning order in the screen of a map display device.</p> |
