Sequence Detector is a digital system which can detect/recognize a specified pattern from a stream of input bits. Let’s say the Sequence Detector is designed to recognize a pattern “1101”. Consider input “X” is a stream of binary bits. When…
Category: Digital Electronics
State Machine Synthesis
State machine synthesis is a process of of boiling down a state machine to a digital logic circuit. Steps in State Machine Synthesis Convert the description into state machine Find out the equivalent states and minimize the state machine Encode…
Truth Tables, Characteristic Equations and Excitation Tables of Different Flipflops
Flipflops to be considered are: SR Flipflop JK Flipflop D Flipflop T Flipflop SR Flipflop Truth Table S R Q(t+1) 0 0 Q(t) 0 1 0 1 0 1 1 1 Invalid inputs Characteristic Equation Q(t+1) = R'(t)Q(t) + S(t)…
Mealy to Moore and Moore to Mealy Transformation
Sequential machines can be designed in two different ways: (i) Mealy Machine & (ii) Moore Machine Considering Mealy or Moore for the designing of sequential machine, it’s actually difficult to draw a hard line where one machine is always better…
Mealy Vs. Moore Machine
Design of sequential circuit can be composed of designing combinational circuit and state register. Sequential circuits are implemented in two different ways: Mealy Machine Moore Machine We can represent a sequential machine as M = <I,O,S,f,g>; where I: Input set…
Synopsys – Interview Questions – based on Synthesis and Simulation
This post contains some very interesting interview questions asked by Synopsys the EDA giant in its interview. The questions are based on Verilog Synthesis and Simulation. Though I have included the answers; I would encourage the reader to experiment himself…
Case and Conditional Statements Synthesis CAUTION !!!
Case and Conditional Statements are available in both VHDL and Verilog. These are considered as significant features of behavioral modelling, be it in VHDL or Verilog. Behavioral modelling provides high level abstraction so that the circuit can be designed by…
Circuit Design of a 4-bit Binary Counter Using D Flip-flops
Problem Statement: Design a circuit for an edge triggered 4-bit binary up counter (0000 to 1111). When it reaches “1111”, it should revert back to “0000” after the next edge. Use positive edge triggered D flip-flop (shown in the below…
Difference between Latch and Flip-Flop
Flip-Flop (FF) and Latch are digital electronic circuits that are used to store information in bits as they have two stable states. One FF or latch can store 1 bit of information. FF is a circuit that can be made to…
Difference between Combinational and Sequential logic circuits.
Combinational and Sequential circuits are the most essential concepts to be understood in digital electronics. Combinational logic (sometimes also referred to as time-independent logic) is a type of digital logic which is implemented by Boolean circuits, where the output is…