Programmable Logic Devices (PLDs) are integrated circuits that contain a relatively small number of functional elements that provide user-configurable logic functions (AND, OR, etc.) as well as configurable interconnections between the elements within the device, allowing logic functions of modest complexity to be implemented using fewer components than would be required if individual logic devices were used, and also simplifying the process of making changes to the function being implemented. Devices of this type typically incorporate a non-volatile configuration memory, allowing the programmed functionality to be retained when power to the device is removed.