Apparatus for and method of allocating a shared resource among multiple ports

Apparatus for allocating a shared resource among a plurality of ports, said apparatus comprising:

• an input queue, said input queue divided into a plurality of segments wherein each segment is capable of holding a frame of data;
• scanning means for scanning said plurality of ports in a predetermined manner for a port with a complete frame ready to be processed by said shared resource, wherein ports without a complete frame ready to be processed are ignored;
• write means for writing those frames ready simultaneously to next available segments in said input queue, wherein the order of writing frames to said segments is in accordance with their arrival over said plurality of ports;
• and
• forwarding means for forwarding frame data sequentially from said input queue to said shared resource wherein the order of forwarding frames is the same order in which they were previously written to said input queue.

A multiple input, single output queue, comprising:

• a memory buffer containing a plurality of segment locations, said memory buffer adapted to support the simultaneous writing of frame data from a plurality of ports;
• a scanning mechanism for detecting ports with frame data ready to be processed;
• and
• a controller, said controller operative to:
• and
• wherein frames from a plurality of ports may be written simultaneously to said memory buffer;
• retrieve frames from said memory buffer and output them to said shared resource, wherein the order in which frames are retrieved from said memory buffer is the same order in which they were previously stored in said memory buffer.