Arbitrating and multiplexing circuitry

A method of arbitrating and multiplexing to perform an arbitration between a plurality of inputs and a selection of at least one of said plurality of inputs to provide an output, said method comprising the steps of:

• performing said arbitration with arbitration tree circuitry, said arbitrating tree circuitry having X arbitrating levels, where X is an integer greater than one;
• and
• performing said selection with multiplexing tree circuitry, said multiplexing tree circuitry having Y multiplexing levels, where Y is an integer greater than one;
• wherein
• (i) said Y multiplexing levels comprise a first set of said multiplexing levels upstream of a second set of said multiplexing levels;
• (ii) said first set of said multiplexing levels operates in parallel with at least some of said X arbitrating levels, whereby said first set of multiplexing levels performs a partial selection in parallel with said arbitration performed by said X arbitrating levels;
• and
• (iii) said second set of said multiplexing levels operates in series with said X arbitrating levels, whereby said second set of multiplexing levels completes said selection to provide said output following completion of and in dependence upon said arbitration.

An apparatus comprising:

• arbitration circuitry having at least one arbitration level;
• multiplexing circuitry having a plurality of multiplexing levels;
• wherein:
• a first one of said multiplexing levels is upstream of a second one of said multiplexing levels;
• the first multiplexing level is configured to operate in parallel with the at least one arbitration level;
• and
• the second multiplexing level is configured to operate in series with the at least one arbitration level.

A method comprising:

• performing arbitration using at least one arbitration level;
• and
• performing multiplexing using a plurality of multiplexing levels;
• wherein
• a first one of said multiplexing levels is upstream of a second one of said multiplexing levels;
• the first multiplexing level is configured to operate in parallel with at the arbitration level;
• and
• the second multiplexing level is configured to operate in series with the arbitration level.