Analysis of Hamming EDAC SRAMs Using Simplified Birthday Statistics

In 2009 Tausch developed a simple equation to predict the cumulative probability of a single uncorrectable (double bit) error occurring within Hamming protected memory as the number of random upsets increase. This paper furthers that work by: 1) developing a simplified equation that predicts the number of failing addresses vs. random upsets in Hamming protected memories, 2) showing the range over which this simplified equation matches more complicated, 3) proving the validity of this equation through radiation testing, 4) showing how this equation can be used to improve test techniques in various simulator environments and 5) showing how this equation can be used to better analyze test results and to understand and predict the behavior of Hamming memories in radiation environments. An approach will be described to better calculate upset cross-sections of Hamming protected SRAMs in heavy ion environments.