Fault Tolerant ICAP Controller for High-Reliable Internal Scrubbing

High reliable reconfigurable applications today require system platforms that can easily and quickly detect and correct single event upsets. This capability, however, can be costly for FPGAs. This paper demonstrates a technique for detecting and repairing SEUs within the configuration memory of a Xilinx Virtex-4 FPGA using the ICAP interface. The internal configuration access port (ICAP) provides a port internal to the FPGA for configuring the FPGA device. An application note demonstrates how this port can be used for both error injection and scrubbing (L. Jones, 2007). We have extended this work to create a fault tolerant ICAP scrubber by triplicating the internal ICAP circuit using TMR and block memory scrubbing. This paper will describe the costs, benefits, and reliability of this fault-tolerant ICAP controller.