| 摘要 |
PURPOSE:To reduce the memory capacity by securing such constitution where a memory contains a page mode function, allocates plural screen areas, reads out picture data out of each screen area within one memory cycle and can control independently the screen contents. CONSTITUTION:A memory control circuit 5a gives a column address-enable CAE2 to an address converter 5b and deletes a latch-enable column address- enable CAE1. The converter 5b outputs the column address of a screen area 2b to a memory 2' and then outputs cursor data on the area 2b with the row and column addresses fixed by a column address strobe CAS of the circuit 5a. The circuit 5a gives P/S conversion enable to P/S converters 21 and 22. Thus the converters 21 and 22 output 8-bit series image data and cursor data. Then an OR circuit 4 secures OR for each bit and this result is turned into synthetic image signals and then into video signals with synchronization to be displayed on a display. |
