PCM telephone transmissions switching - uses modular circuit comprising memory controlled multiplexer to switch channels

摘要

A modular circuit employed in a time switching network for pulses code modulated telephone transmissions comprises an integrated matrix. Several types of matrixes are used on a single printed circuit card. A spatial switching module (1) forming part of a larger matrix comprises a multiplexer (2) which 8 channels (a toh) are switched to an output (11) when commanded by a register (3). Data entering or leaving a memory (4) is controlled by a rear write control (9) and depends on memory address information (8) entering an interface (5). Memory output enters the register to control the multiplexer and a gate (6) in the memory loop is controlled from a high impedance input (10).