a2f500m3b-1csh484 Actel Corporation, a2f500m3b-1csh484 Datasheet - Page 11

• Manufacturer Part Number: a2f500m3b-1csh484
• Description: Actel
• Manufacturer: Actel Corporation

Actel SmartFusion Intelligent Mixed Signal FPGAs
brownout detection devices from the PCB design. Flash-based SmartFusion devices simplify total
system design and reduce cost and design risk, while increasing system reliability.
Immunity to Firm Errors
Firm errors occur most commonly when high-energy neutrons, generated in the atmosphere, strike a
configuration cell of an SRAM FPGA. The energy of the collision can change the state of the
configuration cell and thus change the logic, routing, or I/O configuration behavior in an unpredictable
way.
Another source of radiation-induced firm errors is alpha particles. For alpha radiation to cause a soft or
firm error, its source must be in very close proximity to the affected circuit. The alpha source must be in
the package molding compound or in the die itself. While low-alpha molding compounds are being used
increasingly, this helps reduce but does not entirely eliminate alpha-induced firm errors.
Firm errors are impossible to prevent in SRAM FPGAs. The consequence of this type of error can be a
complete system failure. Firm errors do not occur in SmartFusion flash-based FPGAs. Once it is
programmed, the flash cell configuration element of SmartFusion FPGAs cannot be altered by high
energy neutrons and is therefore immune to errors from them. Recoverable (or soft) errors occur in the
user data SRAMs of all FPGA devices. These can easily be mitigated by using error detection and
correction (EDAC) circuitry built into the FPGA fabric.
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