Crosspoint switch with bank-switched memory

Abstract

A crosspoint switch routes signals between its terminals in routing patterns defined by routing data from a host controller. The crosspoint switch includes an array of pass transistors. Each pass transistor, when turned on, provides a signal path interconnecting a separate, unique pair of the switch terminals. The crosspoint switch also includes two static random access memory banks. Each memory bank stores routing data defining a separate routing pattern and produces a separate set of output signals reflecting its stored data. A multiplexer delivers the output signals of a selected one of the memory banks to the switch array for controlling its pass transistors so that the switch array implements the routing pattern defined by the data in the selected memory bank. By loading routing data defining different routing patterns into the two memory banks, a host controller can thereafter quickly make the crosspoint switch alternate between the two routing patterns by toggling the multiplexer's control input.