A charge-sharing circuit includes a first input bus pair, a second input
bus pair, and an output bus pair. A capacitor is coupled between a first
internal node and a second internal node. A first circuit selectively
couples the first internal node to the first input bus pair, the second
input bus pair and the output bus pair. A second circuit selectively
couples the second internal node to the first input bus pair, the second
input bus pair and the output bus pair. A third circuit selectively
couples the first input bus pair to a reference voltage. A fourth circuit
selectively couples the second input bus pair to the reference voltage.
The third circuit is activated when the first input bus pair is inactive
and charge is shared between the second bus pair and the output bus pair.
The fourth circuit is activated when the second input bus pair is
inactive and charge is shared between first bus pair and the output bus
pair.