| 摘要 |
PURPOSE:To attain high speed data transfer in an internal bus line by giving precharge to the internal bus line to an intermediate level of a power voltage in advance. CONSTITUTION:A precharge circuit PR consists of a P-channel MOSFET Q5 receiving a control signal phi'pr at its gate, a P-channel MOSFET Q6 of diode connection, an N-channel MOSFET Q7 whose gate receives a control signal phipr and an N-channel MOSFET Q8 of diode connection. In the stage of the instruction fetch, the control signals phi'pr, phipr are brought respectively into a low and a high level and the internal bus line BL is precharged in advance to the intermediate level. Thus, even when the size of a discharge MOSFET is not made large, the high speed discharge of the bus line is made possible, an undesired capacitive load of the internal bus line based on the discharge MOSFET is decreased and the high speed data transfer in the internal bus line is attained.
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