| 摘要 |
PROBLEM TO BE SOLVED: To speed up access in a rectangular area by dividing a memory array into plural arrays and also avoiding data in the rectangular area set on a pic ture space in a prescribed size from being arranged in a different memory row in the same subarray. SOLUTION: Pixel information of an area consisting of 8×8 pixels on the display screen of 640×480 pixels are stored in a memory array 6. The memory array 6 is divided into 8 subarraies 6-1 to 6-7 respectively consisting of 28 rows×1024 columns. The screen of the display is divided into 60 pieces of blocks for every 8 pixel rows and block numbers of 0 to 59 are added to these blocks. A column address latch 2 outputs column coordinates (0 to 639) as column addresses C of storing memory cells. In row addresses R to be outputted by a row address latch 1, block numbers of the pixel area are allocated in lower 7 bits and row numbers in the pixel area are allocated in upper 3 bits.
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