Telephone exchange switching and control matrix - has shift register connected as close ring to cross-points in matrix and clock pulse stepping

摘要

The switching matrix has MOS transistor cross-points in which the gate capacitance of the MOS transistors is used a store for control information and in which each cross-point is connected to a stage in the controlling shift register. The shift register is connected as a closed ring with the cross-points in the matrix and is fed with a clock pulse, furthermore each stage of the shift register acts as controlling store and operate pulse for the cross-points whilst also incorporating OR-gate functions to test for free inlets and outlets along the two sides of the matrix. The design stores the switching instruction for the speech path in the matrix and uses the peripheral shift register circuitry for all marking, release and testing functions, giving the advantage of low power consumption and system flexibility. DS.