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TITLE: Radiation-Tolerant Design Using LEON
The fault tolerant LEON3 processor in combination with the
radiation tolerant ACTEL RTAX2000S FPGA presents an alternative
to the processors currently used by the space industry. The
processor is offered in standard configurations suitable for
spacecraft and payload control applications. The standard
configurations includes the LEON3FT processor core with
associated IEEE-754 floating-point unit, two SpaceWire links, two
MIL-STD-1553 BRM, two CAN-2.0 interfaces, memory controller with
ECC, timer unit, two UARTs and 16-bit GPIO port. To fit within
the resources of a single RTAX2000S, five application-specific
sub-set configurations have been defined. These configurations
are available as pre-programmed AX2000/RTAX2000S parts in both
commercial and high-rel quality levels.
To confirm the SEU (single event upset) tolerance of the
LEON3FT-RTAX processor, the RTAX2000S part was submitted to Cf-
252 heavy-ion error injection. The error injection lasted for 168
hours, with a heavy-ion flux of 22 particles/s/cm2 at the device
surface. A total of 2,429 SEU errors were registered in the on-
chip block RAMs. All errors were detected and corrected by the
LEON3FT fault-tolerance logic. No anomalies or computational
errors were observed. The effective SEU rate was measured to 0.25
errors/minute.
Simulated error injection using the LEON3FT debug interface was
performed and correlated with the Cf-252 SEU test data. It was
then possible to determine the Cf-252 SEU cross-section for an
RTAX2000S block RAM bit to 2.3E-9 cm2/bit. This value correlates
well with earlier cross-section measurement performed by Actel at
the BNL and TAMU cyclotron facilities, confirming the validity of
the Cf-252 test methodology and obtained results.
For additional information, access: Gaisler
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FILENUMBER: 1265
BEGIN_KEYWORDS
Radiation-Tolerant Design LEON
END_KEYWORDS
DATE: June 2006
TITLE: Radiation-Tolerant Design Using LEON
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