US 5,691,655 A · Bus driver circuit configured to partially discharge a bus conductor to decrease line to line coupling capacitance

Abstract

A driver circuit is provided which unconditionally discharges a bus conductor during clock cycles in which the driver circuit is transmitting a value. The unconditional discharge occurs during a first drive phase of the logic drive state. During a second drive phase, the driver circuit either charges or continues to discharge the conductor based on the data value being transmitted. Since the conductors are transitioning in the same direction at approximately the same rate, line to line coupling is virtually non-existent during the first drive phase. By partially discharging bus conductors during the first drive phase, transition speed is increased to the point at which a receiving circuit senses the transmitted value. Effectively, the line-to-line coupling which would have occurred during the first drive phase is endured during the second drive phase, when certain conductors may be recharged. Shifting the coupling to the second drive phase results in the more rapid transition of the bus signals during the first drive phase.

Claims20

Dependent claims

A driver circuit, comprising:

a first transistor coupled between a ground and a conductor;
a second transistor coupled between a power supply and said conductor;
a first logic circuit coupled to a gate terminal of said first transistor, said first logic circuit further coupled to receive a first signal, wherein said first logic circuit is configured to activate said first transistor during a first drive phase of a logic drive state if said first signal is asserted;
and
a second logic circuit coupled to a gate terminal of said second transistor, said second logic circuit further coupled to receive a second signal, wherein said second logic circuit is configured to activate said second transistor during a second drive phase of said logic drive state if said second signal is deasserted.

2 more elements

Dependencies are inferred from the claim text.

Bus driver circuit configured to partially discharge a bus conductor to decrease line to line coupling capacitance

Life of this patent

Bus driver circuit configured to partially discharge a bus conductor to decrease line to line coupling capacitance

Life of this patent

Abstract

Claims20