The architecture and implementation of the LEON-FT processor is presented. LEON-FT is a fault-tolerant 32-bit processor based on the SPARC V8 instruction set. The processors tolerates transient SEU errors by using techniques such as TMR registers, on-chip EDAC, parity, pipeline restart, and forced cache miss. The first prototypes were manufactured on the Atmel ATC35 0.35 µm CMOS process, and subjected to heavy-ion fault-injection at the Louvain Cyclotron. The heavy-ion tests showed that all of the injected errors (> 100,000) were successfully corrected without timing or software impact. The device SEU threshold was measured to be below 6 MeV while ion energy-levels of up to 110 MeV were used for error injection.• Modularity. The processor implementation should allow reuse in system-on-a-chip (SOC) designs.• Scalability. The processor should be usable in both lowend and high-end applications with minimum hardware and software overhead.

An open-source IP library based on the AMBA-2.0 AHB/APB bus is presented. The library adds "plug&play" capability to the AMBA bus, while maintaining compatibility with existing AMBA cores. The library is both vendor and technology independent, and has support for several commercial tool-chains.

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This paper presents a DVS (Dynamic Voltage Scaling) enabled SoC (System-on-Chip) processing platform based on the Leon3 open-source processor and dynamically reconfigurable clock synthesis technology available in Virtex-4 Xilinx FPGAs. A special DVS monitor unit maintains correct operation of the processor core at a given voltage by tracking the behavior of an internal delay line and stopping the processor clock through a digital clock management (DCM) macroblock when a timing error is about to occur. Upon detection of a new valid working point the DVS monitor unit reconfigures the main DCM to synthesize a new frequency-adjusted CPU clock signal and reactivates the processor. The energy savings and operation range of the technology are evaluated in the context of video coding applications by executing different motion estimation kernels.