Latch Vs. Flip Flop: What is the Difference Between Latch and Flip Flop
The major difference between flip-flop and latch is that the flip-flop is an edge-triggered type of memory circuit while the latch is a level-triggered type. It means that the output of a latch changes whenever the input changes. On the other hand, the latch only changes its state whenever the control signal goes from low to high and high to low.
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What is a Flip-Flop?
A flip-flop is a digital memory circuit that stores one bit of data. They are the primary blocks of the most sequential circuits. It is also called one-bit memory, binary, or a bistable multivibrator. Flip-flops act as memory elements in a sequential circuit. You can obtain the output in the sequential circuits using a flip-flop, a combinational circuit, or both.
A flip-flop state repeatedly changes at an active state of the clock pulses. They remain unaffected even when the clock pulse does not stay active. The clocked flip-flops particularly act as the memory elements of the synchronous sequential circuit- while the un-clocked ones (latches) function as the memory elements of asynchronous sequential circuits.
There are mainly four types of flip-flops:
- JK Flip-Flop
- SR (Set-Reset) Flip-Flop
- Data or Delay (D) Flip-Flop
- Toggle (T) Flip-Flop
What Is a Latch?
A latch is an electronic device that changes its output immediately on the basis of the applied input. One can use it to store either 0 or 1 at a specified time. A latch contains two inputs- SET and RESET, and it also has two outputs. They complement each other. One can use a latch for storing one bit of data. It is a memory device- just like the flip-flop. But it is not synchronous, and it does not work on the edges of the clock like the flip-flop.
Difference Between Flip-flop and Latch
|Flip-flop utilizes an edge triggering approach.
|Latch follows a level triggering approach.
|The clock signal is present.
|The clock signal is absent.
|You can design it using Latches along with a clock.
|You can design it using Logic gates.
|Flip-flop is sensitive to the applied input and the clock signal.
|Latches are sensitive to the applied input signal- only when enabled.
|It has a slow operating speed.
|It has comparatively fast operating speed.
|You can classify a flip-flop into a synchronous or asynchronous flip-flop.
|A user cannot classify the Latch this way.
|Flip-Flops work using the binary input and the clock signal.
|Latches operate only using binary inputs.
|It requires more power.
|It requires comparatively less power.
|Analysis of Circuit
|It is quite easy to perform circuit analysis.
|Analyzing the circuit is quite complex.
|Type of Operation Performed
|Flip-flop performs Synchronous operations.
|Latch performs Asynchronous operations.
|Flip-flops are comparatively more robust.
|Latches are comparatively less robust.
|Dependency of Operation
|The operation relies on the present and past input bits along with the past output and clock pulses.
|The operation depends on the present and past input along with the past output binary values.
|Usage as a Register
|A flip-flop is capable of working as a register as it contains clock signals in its input.
|A latch cannot serve as a register as the register requires further advanced electronic circuits (EC). Time also plays an essential role here.
|J-K, S-R, D, and T Flip-flops.
|J-K, S-R, D, and T Latches.
|It requires more area.
|It requires comparatively less area.
|They constitute the building blocks of many sequential circuits such as counters.
|Users can utilize these for designing sequential circuits. But they are still not generally preferred.
|Input and Output
|A flip-flop checks the inputs. It only changes the output at times defined by any control signal like the clock signal.
|The latch responds to the changes in inputs continuously as soon as it checks the inputs.
|A flip-flop is synchronous. It works based on the clock signal.
|A latch is asynchronous. It does not work based on the time signal.
|Flip-Flops stay protected against any fault.
|The latches are responsive to any occurring faults on the enable pin.
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