Digital Logic · Unit 6 · 10 hrs
Synchronous and Asynchronous Sequential Logic
Exam-focused notes for Synchronous and Asynchronous Sequential Logic (Digital Logic, CSC116): what the TU syllabus asks and how it has actually been tested, with 10 solved past questions from this unit.
What this unit covers
- Flip-Flops
- Triggering of flip-flops
- Analysis of clocked sequential circuits
- Design with state equations and state reduction table
- Introduction to Asynchronous circuits
- Circuits with latches
Flip-Flops
Write about D flip flop with necessary circuit, block diagram, characteristic table and equation. [5]
The D flip flop (Data or Delay flip flop) is a modification of the SR flip flop. It eliminates the ambiguous condition (S=R=1) by ensuring that the two inputs are always complementary. The single input D is connected directly to S and through an inverter to...
Full solved answer →What is drawback of RS Flipflop? Explain D Flip Flop in detail with Logic Diagram, characteristics table and Characteristics equation. [5]
--- The major drawback of the RS Flip Flop is the forbidden/undefined state. When both inputs S = 1 and R = 1 are applied simultaneously, the output becomes unpredictable or indeterminate (i.e., Q and Q' both try to become 1 at the same time, which is a con...
Full solved answer →Design with state equations and state reduction table
Explain state diagram, state table, state reduction and state assignment with suitable example. [5]
--- A state diagram is a graphical representation of a sequential circuit that shows all possible states, transitions between states, inputs, and outputs. Conventions: - Each circle represents a state (labeled with binary number inside) - Directed lines (ar...
Full solved answer →Design the sequential circuit with respect to the following state diagram using T flip flops.[10]
Critical issue: The actual state diagram image is NOT provided in the question. No states, transitions, inputs, or outputs can be read from the prompt. Missing data: - Number of states - State labels and encoding - State transitions (present → next) - Prese...
Full solved answer →Design the sequential circuit with respect to the following state diagram using J-K Flip flops.[10]
Problem statement: Design a sequential circuit for a given state diagram using J-K flip-flops. Critical issue - Missing data: The actual state diagram is not provided in the question. The following required information is unreadable/missing: - The number of...
Full solved answer →Design sequential circuit specified by the following state diagram using T flip-flops.[10]
The actual state diagram image is not provided in this question. The specific states, transitions, inputs, and outputs cannot be read. Any answer therefore depends entirely on assuming a particular state diagram. The working below assumes a 3-bit binary up-...
Full solved answer →Write short notes on (Any two): RTL, State Reduction, POS [5]
--- RTL (Register Transfer Level) is a design abstraction used to describe the operation of a digital circuit in terms of the flow of data between registers and the logical operations performed on that data. - RTL describes how data moves from one register ...
Full solved answer →Design clocked sequential circuit of the following state diagram by using JK flip-flop.[4]
The problem asks to design a clocked sequential circuit from a state diagram using JK flip-flops. Critical issue: The actual state diagram is not provided in the question. The diagram (states, transitions, inputs, outputs) is essential to solve this problem...
Full solved answer →Triggering of flip-flops
How race condition in JK flip flop can be resolved? Explain. [5]
In a JK flip flop, the inputs are: - J (acts like Set) - K (acts like Reset) The truth table of JK flip flop includes the condition: J K Q (next state) ---------------------- 0 0 Q (No change) 0 1 0 (Reset) 1 0 1 (Set) 1 1 Q' (Toggle) When J = 1 and K = 1, ...
Full solved answer →Explain negative-edge triggered D flip flop with necessary logic diagram and truth table. [5]
An edge-triggered flip flop is a flip flop that synchronises its state changes during the clock pulse transition. The output transition occurs at a specific level of the clock pulse. When the pulse input level exceeds this level, the inputs are locked out a...
Full solved answer →Make Unit 6 stick
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