A programmable integrated circuit utilizes a large number of intermediate-grain processing elements which are multibit processing units arranged in a configurable mesh. The coarse-grain resources, such as memory and processing, are deployable in a way that takes advantage of the opportunities for optimization present in given problems. To accomplish this, the interconnect supports three different modes of operation: a static value in which a value set by the configuration data is provided to a functional unit, static source in which another functional unit serves as the value source, and a dynamic source mode in which the source is determined by the value from another functional unit.