Answer
The sequence of events that occurs when the upper input is temporarily set to 1
Work Step by Step
Answer: The sequence of events that occurs when the upper input of a flip-flop is temporarily set to 1 can be described as follows:
Assumption: Assuming that both inputs to the flip-flop in the given figure are initially 0, we need to describe the sequence of events when the upper input is temporarily set to 1.
Sequence of Events:
1. Initial State:
β’ Both inputs to the flip-flop are 0.
β’ The output of the flip-flop (Q) is stable and is determined by the previous state of the flip-flop.
2. Upper Input Set to 1:
β’ When the upper input (letβs call it πS) is temporarily set to 1, the output of the upper OR gate becomes 1 because πS OR anything is 1.
β’ The upper NOT gate receives this 1 and inverts it, producing an output of 0.
3. Propagation through the Lower OR Gate:
β’ This 0 from the upper NOT gate becomes one of the inputs to the lower OR gate.
β’ Since the other input to the lower OR gate is still 0 (because the lower input is initially 0), the lower OR gate produces an output of 0.
4. Lower NOT Gate Output:
β’ The 0 from the lower OR gate is fed into the lower NOT gate.
β’ The lower NOT gate inverts this 0, producing an output of 1.
5. Flip-Flop Output and Feedback:
β’ This output of 1 from the lower NOT gate is the output πQ of the flip-flop.
β’ This 1 is also fed back to the upper OR gate as one of its inputs.
6. Maintaining the State:
β’ When the upper input πS returns to 0, the upper OR gate still has an input of 1 due to the feedback from the flip-flopβs output.
β’ This feedback holds the output of the upper OR gate at 1, keeping the flip-flop in its current state with π=1Q=1.
Conclusion: Even after the upper input πS is set back to 0, the flip-flop output πQ remains 1 because of the feedback loop. This sequence illustrates how a flip-flop can maintain its state using feedback, a fundamental characteristic of flip-flop circuits in digital electronics.
