Programmable logic units are described. A described unit includes one or more input interfaces to receive one or more input signals; logic elements that are individually programmable; one or more output interfaces to provide one or more output signals; and a programmable interconnect array that is configured to selectively form one or more interconnections within the unit based on one or more programming settings. The programmable interconnect array can be programmable to route the one or more input signals from the one or more input interfaces to at least a portion of the logic elements, programmable to route one or more intermediate signals among at least a portion of the logic elements, and programmable to route one or more signals from at least a portion of the logic elements to produce the one or more output signals via the output interface.