Overview of iRoC Technologies’ Report "Radiation Results of the SER Test of Actel, Xilinx, and Altera FPGA Instances"

Particles contained in cosmic galactic rays enter the earth's atmosphere and collide with atoms of atmospheric gases. These collisions produce a wide variety of sub-atomic particles, many of which recombine quickly. However, a significant quantity of high-energy neutrons are also produced by these collisions. Neutrons possess no electrical charge, and do not recombine; instead, they are slowly attenuated by the atmosphere. While the greatest quantities of neutrons (called the neutron flux density) occur at an altitude of 60,000 feet, a significant number of neutrons penetrate the atmosphere and reach the earth's surface. These high-energy neutrons can cause flip-flops and memory cells in modern semiconductor electronics to change state. Given this discovery, the effects of neutrons on programmable logic devices, which use memory cells to determine their functionality, is a major concern. Additionally, plastic package molding compounds contain tiny quantities of radioactive isotopes which emit alpha particles. Many of these alpha particles are sufficiently energetic to cause upsets in data flip-flops and memory cells, including the configuration SRAM memory in programmable logic. In response to this concern, iRoC Technologies has conducted a series of tests to determine the failure rates of five different architectures of field programmable gate arrays (FPGAs), using three different programming technologies from three different vendors.