Abstract: A crosspoint switch includes a large number of ports and a separate pass transistor linking each possible pair of ports. When a pass transistor is turned on or off, it makes or breaks a signal path between the pair of ports it links. Each port can process signals passing through the port in any one of several operating modes, with a current operating mode being selected by input mode control data. The crosspoint switch also includes a random access memory (RAM) having a separate addressable storage location corresponding to each port. Each RAM storage location stores routing data for controlling the pass transistors connected to a corresponding port and also stores mode control data controlling the mode of the corresponding port. A memory controller responds to a parallel command from a host computer by concurrently writing routing and mode control data to two storage location of the RAM, thereby quickly making and/or breaking a signal path between two ports and selecting the operating mode of both ports.