Programmable arbitration system for determining priority of the ports of a network switch

A network switch for relaying data packets between a plurality of network devices, comprising:

• a plurality of network ports to receive and to transmit data packets, each of said plurality of network ports including port status logic to provide status signals indicative of whether a corresponding network port has received data from a network device and whether a corresponding network port has available space to receive data to transmit to a network device;
• and
• a switch manager coupled to said plurality of network ports to control data flow between said plurality of network ports, said switch manager including:
• control logic to select one of a plurality of arbitration schemes;
• a memory to store priority values indicating the relative priority of each of said plurality of network ports, said memory including:
• a receive list, including:
• a receive active bit for each of said plurality of network ports to indicate that a corresponding port has received data from a network device;
• and
• a receive priority count for each of said plurality of network ports indicative of relative priority;
• a transmit list, including:
• a transmit active bit for each of said plurality of network ports to indicate that a corresponding port has space to receive data to transmit to a network device;
• and
• a transmit priority count for each of said plurality of network ports indicative of relative priority;
• monitor logic coupled to said memory and said control logic to monitor each of said plurality of network ports and to program said priority values in said memory based on a priority scheme selected by said control logic;
• and
• arbitration logic coupled to said memory to select a network port having the next highest priority.

A network system, comprising:

• a plurality of network devices;
• and
• a network switch coupled to said plurality of network devices to transfer data packets between said network devices, said network switch comprising:
• a plurality of network ports to receive and to transmit data packets, each of said plurality of network ports including port status logic to provide status signals indicative of whether a corresponding network port has received data from a network device and whether a corresponding network port has available space to receive data to transmit to a network device;
• and
• a switch manager coupled to said plurality of network ports to control data flow, said switch manager including:
• control logic to select one of a plurality of arbitration schemes;
• a memory to store priority values indicating the relative priority of each of the ports;
• monitor logic coupled to said memory and said control logic to monitor each of the ports and to program said priority values in said memory based on a priority scheme selected by said control logic, said monitor logic including polling logic to periodically assert a query signal and to receive a transmit status signal and a receive status signal from each of the ports, wherein said polling logic asserts said query signal and receives a plurality of transmit status signals and a plurality of receive status signals, said polling logic including:
• a receive state machine to monitor said receive status signals and to periodically update a receive list;
• and
• a transmit state machine to monitor said transmit status signals and to periodically update a transmit list;
• and
• arbitration logic coupled to said memory to select a port having the next highest priority.