FPGA Based Fault Tolerant Techniques in VLSI Circuits
Triple Modular redundancy(TMR)
As we can see in Given figure Traditional TMR system consisting of three redundant module voter at the modules output has some short coming which need to be overcome in order to operate in safety critical situation. Its main disadvantage is
Its inability to cope with TMR failures which are caused by multiple fault in modules or for faulty voter.
For Instance If we see roll back recovery if an error occurs then the system is recomputed by TMR recovery but time overhead is introduced there due to re-computation. Hence the traditional TMR system is replaced by new approach to provide fault tolerance and recovery system which is known as Fault recoverable Triple Modular Redundancy (FRTMR).So benefits of FRTMR technique are
1. Uses roll forward approach to avoid re-computation
2. Has the ability to locate and remove latent fault using TMR modules as well as to recover the system from multiple fault.
3. It reuses the available scan chains devoted specially for testability purpose.
4. It is very suitable for real time application by synchronizing the three modules during recovery error masking is always preserved during computation.
According to researches the FRTMR technique has been analytically and experimentally evaluated and compared with the state of the art technique. The proposed technique has been implemented on cyclone III FPGA. The proposed analytical study which will be discussed further shows that in the presence of multiple errors, FRTMR improves the reliability of TMR system. In addition to that the result are taken by injecting the fault in FPGA, The result of FPGA fault injection experiments demonstrate that FRTMR can detect and correct 100% and 90% of multiple fault effecting signal or double module.
References:
- FPGA Based Multiple Fault Tolerant and Recoverable Technique Using Triple Modular Redundancy (FRTMR) By Shubham C. Anjankara ,Dr. Mahesh T. Kolteb , Ajinkya Pundc ,Pratiksha Kolted ,Ankita Kumare ,Pranav Mankarf ,Kunal Ambhoreg
