| 摘要 |
PURPOSE:To realize the connection of a kind of the memory card to each CPU by giving the refreshment to two kinds of CPU's with the refresh signal and the chip enable signal. CONSTITUTION:In case the memory card is connected to the 1st CPU, therminal C features logic 1. Timing circuit 2 is inactive when no refresh signal (a) arrives at terminal A. When chip enable signal (b) is supplied to terminal B, signal R/W is delivered from OR circuit 5 to actuate the memory. When signal (a) arrives at terminal A, the signal is transmitted twice from circuit 5 via the output of circuit 2. Then the address designation is given at FF6, and the two addresses of the memory chip are refreshed. While with connection of the card to the 2nd CPU, terminal C features 0. And the refreshment is given when signal (b) arrives at terminal B. |
