# what is triplication on fpga?

I know FPGA design using VHDL and I came up some new topic recently that usage of triplication in FPGA but I am not confident about its understanding.

How can we use triplication in FPGA design and how do we verify this.

• i don"t know what it is either, but why do you need to use it if you don't know what it is? – jsotola May 31 '19 at 6:22
• This is the enhancement to the current design strategy. – srihari May 31 '19 at 6:50
• @srihari we'll need more context. "Triplication" is an English word and means "to make everything be there three times". But it's not clear how this would apply to VHDL design; if you just put the same VHDL modules there three times and then combined the results, the synthesizer will just optimize away two of them, because that's what synthesizers do: analyze the logic of a circuit and reduce it to the correct minimal amount of logic elements necessary to produce the same result. – Marcus Müller May 31 '19 at 7:06
• The Ramans did everything in threes... – htmlcoderexe May 31 '19 at 20:41

Triplication means (as noted) to make 3 of everything.

It is used in space and safety critical designs, and data results are voted; a disagreement in the vote has to be designed such that the erroneous result circuit is reset. For this to work within a single device, partial reconfiguration in the FPGA is required.

The reason this is necessary in SRAM based FPGA devices is that they are susceptible to single event effects (such as SEUs) which can flip a configuration bit from 0 to 1 or vice versa and therefore changing the effective circuit.

SEUs are caused primarily by high energy free neutrons and cosmic radiation (in space applications) although the lead in SnPb solder (in particular those on BGA devices) can also emit alpha particles as some of the lead is $$\Pb ^{210}\$$ which decays via $$\Bi^{210}\$$ and $$\Po^{210}\$$ to $$\Pb^{206}\$$ (Uranium decay chain) which is the stable state for lead.

Flash based devices are immune to configuration state changes from free neutrons although they can be susceptible to X-Ray, and the data path can be protected by parity or ECC.