A switch box (2) for a programmable gate array including input ports grouping a plurality of inputs (I, I′) and output ports grouping a plurality of outputs (O, O′), with the inputs and the outputs being connected to a downstream connection tree structure from the inputs toward the outputs and including routing elements (4, 5, 6) organized according to several levels for connecting by a single path each input of all the input ports to at least one output of each output port.Switch boxes, logic units and programmable gate arrays including these, which are so arranged as to define a single path between two points of the array.