Master-slave configuration is a common technique used in digital systems, including flip-flops (FFs), to eliminate the race around condition. A race around condition occurs when there is a timing mismatch between the inputs of a flip-flop, leading to unpredictable behavior.

Master-slave configuration involves connecting two flip-flops together, where one acts as the master and the other as the slave. The master flip-flop receives the input signals and generates the output signals, while the slave flip-flop holds the output signals and provides them as inputs to the master flip-flop in the next clock cycle.

By using a master-slave configuration, the race around condition can be eliminated because the inputs to the slave flip-flop are only updated when the clock signal transitions from low to high. This ensures that the inputs to the slave flip-flop are stable and do not change during the evaluation phase of the master flip-flop.

Below are the reasons why master-slave configuration in FF eliminates race around condition:

1. Dual-phase clocking: In a master-slave configuration, the clock signal is divided into two non-overlapping phases. The master flip-flop is triggered by the first phase of the clock signal, while the slave flip-flop is triggered by the second phase. This ensures that the inputs to the slave flip-flop are stable before they are used by the master flip-flop, eliminating any timing mismatch.

2. Non-overlapping clock edges: The non-overlapping clock phases ensure that the master and slave flip-flops do not overlap in their operation. This means that the outputs from the master flip-flop are not affected by any changes in the inputs during its evaluation phase, as the slave flip-flop is only updated during the second phase of the clock.

3. Synchronization: The master-slave configuration provides synchronization between the input and output signals of the flip-flop. The master flip-flop captures the input signals and generates the output signals, while the slave flip-flop holds the output signals until the next clock cycle. This ensures that there is no timing mismatch between the inputs and outputs, preventing the race around condition.

Overall, the master-slave configuration in flip-flops eliminates the race around condition by dividing the clock signal into two non-overlapping phases and ensuring synchronization between the inputs and outputs. This improves the reliability of the flip-flop and ensures predictable behavior in digital systems.