| 摘要 |
PROBLEM TO BE SOLVED: To obtain a frame memory in which needless memory, needless write- in/read-out of data, and disturbance of a screen are prevented, and various image can be expressed with simple constitution of a circuit. SOLUTION: This frame memory circuit is a command control type, memory elements consisting of DRAM specifying an access word by row and column addresses are used, this memory element generates a memory access basic command cycle of a read-command or a write-command alternately, a read- command or a write-command is permitted only if necessary or a write-in/read- out counter is sequentially increased in the direction of row, when it exceeds the maximum value of the memory element, a column is increased, operation for restoring a row to the minimum value is performed, and a refresh-cycle is eliminated.
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