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Flip - Flops

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Flip - Flops Flip - Flops are sequential digital circuits that are synchronous bistable devices and can store stable states(1 , 0)  of information. They are also known as bistable multivibrators . Output of the flip-flop changes only when a certain point (either the rising or falling edge) on the triggering input called C lock(CLK) . An edge-triggered flip-flop only changes its state when the clock pulse shifts from low to high – rising edge(positive edge) or high to low-falling edge (negative edge), and it only responds to its inputs during these clock transitions. There is a difference in the logic symbols for positive edge-triggered and negative edge-triggered flip-flops.The negative edge-triggered flip-flop symbol is similar to the positive edge one  but with an inversion bubble or small circle added to the clock input line, indicating that the flip-flop responds to the falling edge (negative edge) of the clock signal. Here is an example of the logic symbol for a D ...
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Gated D - Latch

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Gated D - Latch In a D latch, there's a single data input, labeled D, in addion to the enable input. When the enable input is HIGH and the D input is HIGH, the Q output will be HIGH. When the  enable input is HIGH and the D input is LOW, the Q output will be LOW. In simpler terms, the input provide to the D input is reflected ath the Q output when the enable input is HIGH. When the enable input is LOW, the Q output retains its state, maintaining it held before the enable input transitioned to a LOW state. Function Table of Gated D Latch Waveforms with Gated D Latch If the above waveforms are applied to  Gated D latch .  Draw the resulting Q waveform assuming Q starts RESET(0).  The Q resulting waveform  is as follows.
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The S - R Latch as a Contact-Bounce Eliminator

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The S - R Latch as a Contact-Bounce Eliminator Contact bounce is a common problem that occurs when a mechanical switch or button is pressed or released.Instead of making a smooth and instantaneous transition from open to closed or  vice versa , the contacts may rapidly make and break contact several times before settling into a stable state.      Case 1: When the first switch connects to terminal A , the voltage at terminal B is zero. However , due to the bouncing phenomenon associated with the switch , the voltage at terminal A fluctuates several times before stabilizing at 5v.   Case 2 :  When the second switch connects to terminal B , the voltage at terminal A is zero. The voltage at terminal B undergoes several fluctuations before settling at 5v. To avoid the issue of contact bounce in a switch , the A and B terminals are connected through a active HIGH input S- R latch(NOR gate based S-R latch). Additionally , the outpus of terminals A and B can...
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Gated S - R Latch

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 Gated S - R Latch Gated S - R latches are different from regular S - R latches because they have a special input called "Enable". When the Enable input is HIGH, the latch responds to variations in the S, R inputs . when the enable input is LOW, the latch retains its previous state. Function Table of the Gated S - R Latch   Waveforms with Gated S - R Latch If the above waveforms are applied to  Gated S - R latch .  Draw the resulting Q waveform assuming Q starts RESET(0).  The Q resulting waveform  is as follows.
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Waveforms - [S - R Latch]

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Waveforms - S' - R' Latch If the above waveforms are applied to    Active LOW input S’-R’ Latch .  Draw the resulting Q waveform assuming Q starts LOW.  Use the truth table of the Active LOW input S' - R' latch to draw the resulting waveform. The Q resulting waveform  is as follows. Waveforms - S - R Latch If the above waveforms are applied to    Active HIGH input S -R  Latch .  Draw the resulting Q waveform assuming Q starts LOW. Use the truth table of the Active HIGH input S - R latch to draw the resulting waveform. The Q resulting waveform  is as follows.  
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Active LOW input S’-R’ Latch

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Active LOW input S’-R’ Latch  NAND Gate based S'- R' Latch In the Active LOW input S’-R’ Latch, the latch changes its state based on inputs that are in the LOW logic state.                                     S’(Set) input is active LOW, Latch will be Set(Q = 1)                                   R’(Reset) input is active LOW, Latch will be Reset(Q = 0) Active LOW input S’-R’ Latch implemented with two cross coupled NAND gates produces two complementary outputs , denoted as Q and Q’. When Q is LOW , Q’ is HIGH. When Q is HIGH , Q’ is LOW.                               ...
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Active HIGH Input S-R Latch

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                                    LATCHES The latch is a type of bistable logic device [bistable : A digital circuit that has two gating inputs and output] and temporary storage device that hold single bit of information. Types of latches : SR Latch D Latch SR (SET - RESET) Latch Active HIGH input SR Latch -  [NOR Gate based SR Latch] In the Active HIGH input SR Latch, the latch changes its state based on inputs that are in the HIGH logic state.                                          S(Set) input is active HIGH, Latch will be Set(Q = 1)                     R(Reset) input is active HIGH, Latch will be Reset(Q = 0) Animation of Active HIGH input S-R Latch Case 1: R = 1      S = 0        ...
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