Addiguration: Exploring configuration behavior of Spartan-3 devices

Reconfigurability of FPGAs is an enabler for many applications. In recent years a lot of different reconfiguration approaches and methodologies were presented, including full and partial reconfiguration of devices. In this paper we present the novel methodology of addiguration for Xilinx Spartan-3 devices. Our proposed methodology exploits special properties of the configuration logic and enables to incrementally configure on top of an existing design already running on an FPGA. This work demonstrates a basic technology that might be exploited for testing scenarios or as an entry vector for attacks on FPGA designs. Prototypical experiments have shown that the addiguration can easily be carried out during runtime of the device and over a standard configuration interface.