Describe Triple Modular Redundancy (TMR) and its voting mechanism.

Describe Triple Modular Redundancy (TMR) and its voting mechanism.

• A. Run triplicate computations with a majority vote to select the output; if one path disagrees, its result is discarded.
• B. Use two identical paths with a two-to-one voter.
• C. Use a single path with error-checking CRC.
• D. Use a dynamic reconfiguration to replace faulty path automatically.

Answer: (A)

Triple Modular Redundancy is a fault-tolerance technique that runs three identical computations in parallel and uses a majority voter to decide the final output. The voter compares the three results and outputs the value that appears at least twice; if one path is faulty and its result disagrees, the other two agree on the correct value and that is chosen, effectively masking the fault. This lets the system continue operating correctly as long as fewer than two paths fail. Using only two parallel paths with a two-to-one voter can’t reliably determine the correct result when one path fails, because there’s no majority to resolve a mismatch. A single path with error-checking CRC only detects errors, it doesn’t provide fault tolerance or mask faults. Dynamic reconfiguration to replace a faulty path describes a different fault-management strategy rather than the standard TMR voting mechanism.

Triple Modular Redundancy is a fault-tolerance technique that runs three identical computations in parallel and uses a majority voter to decide the final output. The voter compares the three results and outputs the value that appears at least twice; if one path is faulty and its result disagrees, the other two agree on the correct value and that is chosen, effectively masking the fault. This lets the system continue operating correctly as long as fewer than two paths fail.

Using only two parallel paths with a two-to-one voter can’t reliably determine the correct result when one path fails, because there’s no majority to resolve a mismatch. A single path with error-checking CRC only detects errors, it doesn’t provide fault tolerance or mask faults. Dynamic reconfiguration to replace a faulty path describes a different fault-management strategy rather than the standard TMR voting mechanism.