Digital Electronics And Logic Design

Flip-flop is a circuit that maintains a state until directed by input to change the state. A basic flip-flop can be constructed using four-NAND or four-NOR gates. Types of flip-flops: RS Flip Flop JK Flip Flop D Flip Flop T Flip Flop Logic diagrams and truth tables of the different types of flip-flops are as follows: S-R Flip Flop : J-K Flip Flop: D Flip Flop : T Flip Flop : Conversion for Flip-Flops:- EXCITATION TABLE : Steps To Convert from One FlipFlop to Other  : Let there be required flipflop to be constructed using sub-flipflop: Draw the truth table of the required flip-flop. Write the corresponding outputs of sub-flipflop to be used from the excitation table. Draw K-Maps using required flipflop inputs and obtain excitation functions for sub-flipflop inputs. Construct logic diagram according to the functions obtained. i) Convert SR To JK FlipFlop Excitation Functions: ii) Convert SR To D FlipFlop: Excitation Functions: S = D R = D ‘ Applications of Flip-Flops These are the variou

We discussed various combinational circuits in earlier chapters. All these circuits have a set of output s s , which depends only on the combination of present inputs. The following figure shows the  block diagram  of a sequential circuit. Figure: S equential Circuit This sequential circuit contains a set of inputs and output s s . The output s s  of the sequential circuit depend not only on the combination of present inputs but also on the previous output s s . The previous output is nothing but the  present state . Therefore, sequential circuits contain combinational circuits along with memory  s t o r a g e s t o r a g e  elements. Some sequential circuits may not contain combinational circuits, but only memory elements. The following table shows the  differences  between combinational circuits and sequential circuits. Combinational Circuits Sequential Circuits Outputs depend only on present inputs. Outputs depend on both present inputs and present state. The feedback path is not pr

ASSIGNMENT-1 1. a) Convert the decimal number (37.125)10 into binary, octal and hexadecimal 1. b) Represent the decimal number 369 in Binary and BCD 2. a) Define Minterm and Maxterm 2. b) Find the canonical POS form of Y= A+B’C, F(a, b, c) = a’b + b’c + ac 3. a) Reduce the following Boolean expression i)xy’z + x’y’z + xyz. ii)W’X(Z’+YZ) + X(W+Y’Z). 3. b) Prove Demorgan’s theorem & Find the compliment of expression xyz + xyz’ + xy’z 4. a) define prime implicants, essential prime implicants 4. b) Minimise F (x1, x2, x3) = p M (0,1,2,3,4,5,6) using k map 5. Minimize the following expression using K-Map into SOP and POS forms. Realize them with NAND gate only and NOR gate only F (A, B, C, D) = Ʃm(0,2,4,9,12,15)+d(1,5,7,10) 6. Simplify using Quine – Mccluskey method F (a, b, c, d) = S m (1, 2, 3, 5, 7, 9, 10, 11, 13, 15) 7. a) Explain the representation of signed binary numbers 7. b) Explain the implementation of adder/subtractor circuit 8. Implement the follo

Experiment 11 Aim:- To study R-S clocked R-S, D and clocked D flip–flop. Apparatus:- Flip – flop trainer kit, patch chords. Theory:- A flip–flop Is a bistable electronic circuit that has two stable states i.e. its output is either 0 or +5V dc. The additional input of these gates provides a conventional means for the application of input signals to switch the flip–flop from one stable state to another. Two input NAND gates are connected to form a flip–flop circuit. These two inputs are R & S. The flip–flop has two outputs terms as Q and . if the flip–flop is put into one state it will remain in that state as long as power is applied or until it is changed. In a digital circuit, flip–flops are used in storage, counting, sequencing and timing applications. R-S FLIP FLOP WITHOUT CLOCK The R–S flip–flop is the simplest. It has two inputs, S & R, and two outputs Q and . Appling the appropriate logic level to either S or R input, it will put the latch into one state or the other. When