A Self-Scrubber for FPGA-Based Systems

Scrubbing is generally used in conjunction with triple modular redundancy (TMR) to increase the reliability of FPGA systems in space borne applications. We present in this paper a scrubber solution labeled Femto, currently being developed at Micro-RDC. Femto is a RISC, 8-bit, 9-instruction microcontroller specifically designed for scrubbing memories. The self-scrubber based on Femto occupies \u3c 600 slices and operates at 100 MHz. It has the capacity to calculate a CRC codebook of up to 1024 words on the fly and to use it to detect errors. Femto can be configured to perform blind scrubbing or readback-detect-correct type of operations. It also supports frame-based scrubbing, which allows a user to develop custom scrubbing techniques that better adapts to a specific system\u27s requirements