| 摘要 |
PURPOSE:To prevent a bus from long occupation and to improve the using efficiency of the bus by transferring data intermittently when the large volume of data are to be transferred. CONSTITUTION:An oscillator 5 of which oscillation frequency and duty ratio can be set from the external is formed. When a transfer request signal is outputted from a memory or an I/O, AND between a bus using request signal outputted from a data transfer control circuit 4 and an oscillation output from the oscillator 5 is found out by an AND gate 6 and outputted as a bus request signal. Only in the period that the AND is ''1'', the bus is used and data is transferred, and in the ''0'' period, the bus is made idle to be used for other devices. |
