Actel

Soft/Firm Errors

Neutron ImmuneProgrammable logic devices based on SRAM technology, used in high-reliability applications at ground level and high altitudes, are susceptible to single-event errors where alpha and neutron radiation causes loss of configuration data. The loss of the underlying FPGA configuration is called a "firm error", and it will remain until detected and corrected. In contrast, a "soft error" is the transient corruption of a single bit of data. Firm errors can cause system-level functional failure, and are very difficult to prevent and correct.

Features and Benefits

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Neutron and alpha radiation do not have adverse effects on Actel antifuse and flash-based FPGAs. Actel offers extremely reliable FPGAs for many applications, including military, aerospace, industrial control, medical, automotive, networking, and communications.

Key Benefits
  • Actel antifuse and flash-based FPGAs are not susceptible to configuration loss due to single-event errors (SEE) caused by alpha or neutron radiation
  • No SEE mitigation techniques for configuration upsets are required in Actel FPGAs, reducing overall system cost
  • Actel FPGAs maintain system integrity at high altitudes and sea level

Testing and Results

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An independent organization, iRoC Technologies, conducted both neutron and alpha testing on FPGAs using three different programming technologies, with five different architectures from three major FPGA vendors. The FPGAs were tested until a significant number of failures were observed. Based on these results, the Failures-In-Time (FIT) rates were calculated.
Neutron Radiation Test Results Summary
FPGA Technology Equivalent FIT Rates per Device
Ground-level
Applications		 Commercial
Aviation		 Military
Aviation
Sea Level 5,000 ft 30,000 ft 60,000 ft
Actel AX1000
(1 M Gate)		 0.15 µm
Antifuse		 No Failures Detected No Failures Detected No Failures Detected No Failures Detected
Actel APA1000
(1 M Gate)		 0.22 µm
Flash		 No Failures Detected No Failures Detected No Failures Detected No Failures Detected
Actel A3PE600
(600 K Gate)		 0.13 µm
Flash		 No Failures Detected No Failures Detected No Failures Detected No Failures Detected
SRAM FPGA
(Vendor 1 – 3 M Gate)		 0.15 µm
SRAM		 1,150 FITs 3,900 FITs 170,000 FITs 540,000 FITs
SRAM FPGA
(Vendor 1 – 1 M Gate)		 90 nm
SRAM		 320 FITs 1,100 FITs 47,000 FITs 150,000 FITs
SRAM FPGA
(Vendor 2 – 1 M Gate)		 0.13 µm
SRAM		 460 FITs 1,600 FITs 67,000 FITs 220,000 FITs
SRAM FPGA
(Vendor 2 – 1 M Gate)		 90 nm
SRAM		 730 FITs 2,500 FITs 108,000 FITs 346,000 FITs
SRAM FPGA
(Vendor 2 – 2 M Gate)		 90 nm
SRAM		 1,600 FITs 5,500 FITs 236,000 FITs 751,000 FITs
Alpha Radiation Test Results Summary
FPGA Technology Configuration Upsets Functional Failures Equivalent FIT Rates (FITs)
Low-Alpha Mold Compound
(0.001 α/cm2-hr)		 Standard Mold Compound
(0.04 α/cm2-hr)
Actel AX1000
(1 M Gate)		 0.15 µm
Antifuse		 Not Measured * 0 No Failures
Detected		 No Failures
Detected
Actel APA1000
(1 M Gate)		 0.22 µm
Flash		 Not Measured * 0 No Failures
Detected		 No Failures
Detected
SRAM FPGA
(Vendor 1 – 3 M Gate)		 0.15 µm
SRAM		 1,040 140 140 5,600
SRAM FPGA
(Vendor 1 – 1 M Gate)		 90 nm
SRAM		 940 260 260 10,400
SRAM FPGA
(Vendor 2 – 1 M Gate)		 0.13 µm
SRAM		 Could not be measured 100 100 4,000
* Design security features in Actel FPGA solutions prevent configuration read back.

Resources

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