Method and apparatus for horizontally slicing a multi-stage switch fabric

A switching fabric comprising:

• a first and a second logic device, each of the first and second logic devices including a plurality of switch elements, the first and second logic devices being physically separate from one another;
• a selector that enables signals to be transmitted from the second logic device to a respective output of the first logic device,
• a first routing pattern between the switch elements, and
• a second routing pattern between the switch elements, the second routing pattern being different than the first, the first logic device being initially configured based on the first routing pattern, the first logic device being reconfigured based on the second routing pattern to expand or contract a size of the switching fabric such that a quantity of paths from each switch element input to each switch element output is identical for each fabric size.

A method for constructing a switching fabric, comprising:

• partitioning a switching fabric into at least a first and a second logic device such that the first logic device includes at least two switch elements;
• partitioning at least one of the two switch elements into smaller sub-switch elements when the switch is operated as a first size switching fabric and not partitioning the two switching elements into smaller sub-switch elements when the switch fabric is operated as a second size switching fabric, wherein a quantity of paths through the switching fabric from each transmission input to each transmission output remains constant for each switch fabric size;
• and
• operating a selector to transmit signals from the second logic device to a respective output of the first logic device.

A logic device configured to be used in a switching fabric, the logic device comprising:

• a plurality of inputs each configured to receive a signal at the logic device;
• a plurality of outputs each configured to transmit a signal from the logic device;
• at least two switch elements, wherein at least one of the switch elements is partitioned into smaller sub-switch elements when the switching fabric is operated as a first size fabric, and the other switch element is not partitioned into smaller sub-switch elements when the multi-stage switching fabric is operated as a second size fabric, wherein a quantity of paths through the switching fabric from each input to each output remains constant for each switch fabric size;
• and
• at least one selector that is configured to receive at least one of a signal that is generated internally by the logic device or a signal that is generated externally from the logic device, and transmit the internal or external signal to a respective output of the logic device.