| 摘要 |
PURPOSE:To perform the refreshing of a memory without lowering the processing speed of a CPU, by producing a control signal for a dynamic RAM which should be refreshed synchronously with the first half period of a system clock and within said period. CONSTITUTION:A system clock E is processed to produce a raster address strobe signal and a column address strobe signal. These signals are combined with the output signal of a refresh counter 32 and the output signal of a data selector 25. Thus a control signal synchronized with the first half of the clock E is obtained. Thus a dynamic RAM is refreshed based on the control signal. It is not necessary to set especially a refresh period or to extend the system clock. As a result, a memory can be refreshed without lowering the processing speed of a CPU. |
