1. A data processing system, comprising: a programmable logic device including configurable logic elements, a configuration store, and configuration select logic all located within the programmable logic device, the configuration store storing a set of configuration words defining respective logic functions of the configurable logic elements in the programmable logic device, and the configuration select logic operating to apply a selected configuration word from the set of configuration words to configure the configurable logic elements; an instruction store for storing a sequence of instructions for execution by the programmble logic device, the instructions including a configuration identifier field indicating a selected configuration word in the set of configuration words, each of the identifier fields in the sequence including fewer bits than the number of bits of the selected configuration word; and logic coupled with the instruction store and the configuration select logic the sequencing logic causing the configuration select logic to apply to the configurable logic elements, during respective execution cycles and in response to the receipt of the sequence of instructions stored in the instruction store, selected configuration words from the configuration store as identified by the instructions.