Abstract: A self-adjusting precharge level circuit for coupling to an N-channel precharged bus line. The precharge circuit comprises first, second, and third N-channel transistors and first and second inverters. The first transistor couples the bus line to a positive power supply voltage terminal during a precharge period when the voltage on the bus line falls below the positive power supply voltage minus an N-channel MOS transistor threshold. The second and third transistors together couple the bus line to a second power supply voltage terminal during the precharge period when the voltage level of the bus line rises above positive power supply voltage minus the N-channel MOS therehold, after the voltage level is sensed by the first and second inverters. Sensing and adjusting the voltage in this manner allows the circuit to maintain an N-channel precharge level on a bus which has circuits driving CMOS levels coupled to it, while dampening the voltage response and suppressing oscillation.

Abstract: A clock monitor circuit and method for providing an indication at the output thereof of the presence of an input clocking signal. If the clock input is operating properly, two charge storage nodes will be charged and the output of the circuit will be high. If the clock input is stuck, the output of the clock monitor circuit will be low.

Abstract: A power multiplexer switch for alternatively coupling a supply or standby voltage line to an output voltage line comprises a first switching means for coupling an intermediate node to a common voltage line. Second switching means are responsive to the first switching means for coupling the supply voltage line to the output voltage line. Third and fourth series switching means connected to the intermediate node couple the standby voltage line to the output voltage line when a voltage on the standby voltage line exceeds that on the supply voltage line.