Network switch with zero latency flow control

A network switch for routing data between network stations, the network switch comprising:

• a plurality of output ports, each output port including an output port buffer for receiving and storing data, each output port generating an output FULL signal when its output port buffer is storing a predetermined minimum amount of data, and each output port forwarding data stored in its output port buffer to a separate one of said network stations;
• a plurality of input ports, each receiving data from a separate one of said network stations;
• a switch connected to said input ports and to said output ports for selectively providing a path for a data transmission from any input port to any output port in response to routing control data provided as input to said switch;
• and
• a routing arbitrator connected to said switch for providing said routing control data as input thereto, connected to each of said input ports for receiving routing requests therefrom, and connected to each of said output ports for receiving a FULL signal therefrom,
• wherein when any one of said input ports receives data from a network station, the receiving input port stores the data and transmits a routing request to said routing arbitrator requesting said routing arbitrator to grant the routing request by providing routing control data to said switch causing said switch to provide a path through which the receiving input port may transmit the data to a requested one of said output ports,
• wherein said routing arbitrator refrains from granting routing requests to any requested output port while the output port is asserting its FULL signal, and then grants the routing request after the requested output port stops asserting its FULL signal,
• wherein each output port of said plurality of output ports is connected both to said switch and to said routing arbitrator through a conductor, said conductor conveying data from the switch to the output port and also conveying said FULL signal from said output port to said routing arbitrator,
• wherein each output port of said plurality of output ports asserts said FULL signal by driving said conductor to a particular logic level and deasserts said FULL signal by tristating said conductor, and
• wherein each input port of said plurality of input ports is connected both to said network switch and to said routing arbitrator through a conductor, said conductor conveying data from said input port to said switch means and conveying routing requests from said input port to said routing arbitrator.