Patent ID: 7145378
Filing Date: 2006-12-05
Classification: H03K,H04L

Abstract:
1. A bus switch for electrically making and breaking a plurality connections between a first and a second circuit comprising: a plurality of transfer transistor switches, each arranged as one of the plurality of connections, a plurality of programmable logic inputs, wherein the logical combinations of the states of the programmable logic inputs define different configurations of the transfer transistor switches in a make or break state, and wherein the different configurations run from no switches in a make state to one or more switches, in any combination, in a make state, logic circuitry that accepts the plurality of logic inputs and provides a corresponding plurality of enable outputs connected to the transfer transistor switches, wherein the enable outputs make and break the transfer transistor switches in any of the different configurations in accordance with the programmable logic inputs, selectable level shifting circuitry that provides a reference voltage to control terminals on the transfer transistor switches that is lower than that of the first circuit, a level select input that enables the level shifting circuitry when true and disables it when false, so that when false there is no level shifting, and wherein the logic inputs comprise a first set of programmable logic inputs that selects a configuration with a number of groupings of transfer transistor switches and a second set of programmable inputs that determine the make or break state of drive each transfer transistor switch within each grouping.