Categorization and SEU Fault Simulations of Radiation-Hardened-by-Design Flip-Flops

In the previous three decades, many Radiation-Hardened-by-Design (RHBD) Flip-Flops (FFs) have been designed and improved to be immune to Single Event Upsets (SEUs). Their specifications are enhanced regarding soft error tolerance, area overhead, power consumption, and delay. In this review, previously presented RHBD FFs are classified into three categories with an overview of each category. Six well-known RHBD FFs architectures are simulated using a 180 nm CMOS process to show a fair comparison between them while the conventional Transmission Gate Flip-Flop (TGFF) is used as a reference design for this comparison. The results of the comparison are analyzed to give some important highlights about each design.

Study of single event upsets (SEUS) a survey and analysis

Over the last few years evolution in electronics technology has led to the shrinkage of electronic circuits. While this has led to the emergence of more powerful computing systems it has also caused a dramatic increase in the occurrence of soft errors and a steady climb in failure in time (FIT) rates. This problem is most prevalent in FPGA based systems which are highly susceptible to radiation induced errors. Depending upon the severity of the problem a number of methods exist to counter these effects including Triple Modular Redundancy (TMR), Error Control Coding (ECC), scrubbing systems etc. The following project presents a simulation of an FPGA based system that employs one of the popular error control code techniques called the Hamming Code. A resulting analysis shows that Hamming Code is able to mitigate the effects of single event upsets (SEUs) but suffers due to a number of limitations.

Study of single event upsets (SEUS) a survey and analysis

Over the last few years evolution in electronics technology has led to the shrinkage of electronic circuits. While this has led to the emergence of more powerful computing systems it has also caused a dramatic increase in the occurrence of soft errors and a steady climb in failure in time (FIT) rates. This problem is most prevalent in FPGA based systems which are highly susceptible to radiation induced errors. Depending upon the severity of the problem a number of methods exist to counter these effects including Triple Modular Redundancy (TMR), Error Control Coding (ECC), scrubbing systems etc. The following project presents a simulation of an FPGA based system that employs one of the popular error control code techniques called the Hamming Code. A resulting analysis shows that Hamming Code is able to mitigate the effects of single event upsets (SEUs) but suffers due to a number of limitations.

Precise Cache Profiling for Studying Radiation Effects

Increased access to space has led to an increase in the usage of commodity processors in radiation environments. These processors are vulnerable to transient faults such as single event upsets that may cause bit-flips in processor components. Caches in particular are vulnerable due to their relatively large area, yet are often omitted from fault injection testing because many processors do not provide direct access to cache contents and they are often not fully modeled by simulators. The performance benefits of caches make disabling them undesirable, and the presence of error correcting codes is insufficient to correct for increasingly common multiple bit upsets. This work explores building a program’s cache profile by collecting cache usage information at an instruction granularity via commonly available on-chip debugging interfaces. The profile provides a tighter bound than cache utilization for cache vulnerability estimates (50% for several benchmarks). This can be applied to reduce the number of fault injections required to characterize behavior by at least two-thirds for the benchmarks we examine. The profile enables future work in hardware fault injection for caches that avoids the biases of existing techniques.