What is the Difference Between Latches and Flip Flops?

What is difference between latches and flip flops? Lets first learn what are the latches? A Latch is a circuit component that adjusts the yield dependent on the current info, past input, and past yield. It is exceptionally more straightforward in its development as we need to send the contributions to it and would get the yields on the opposite side. There are four unique sorts of locks and they are as per the following.

What is SR latch?

It is one of the least difficult electronic circuits worked with two ‘NOR’ doors. Here the yield of the principal entryway is sent as one of the contributions to the second and the other way around. The two genuine data sources are by and large alluded as ‘Set’ – ‘Reset’ and henceforth it has the name as SR hook. Simply take a gander at sources of info and yields of this Latch in the underneath picture. The table in the image is alluded as truth table and addresses the data sources and yields in a less complex plain structure. Here, ‘S’ and ‘R’ are the contributions to the rationale doors and ‘Q’ and ‘Q’ are the yields

Working of SR Latch Using NOR Gate

Working of SR Latch Using NAND Gate

What is D latch?

It has got different names like Data Latch, Transparent Latch or Gated Latch. Here, there is only a single input and the output varies based on a control signal named as ‘Enable’ signal. Here is the input and output combination of D latches with respect to the enable signal.

Working of D-type Flip-flop (Transparent latch)

Working of Edge-triggered D Flip-flop

What is JK latch?

It has been developed to overcome the switching problems with the SR latches. From the below image, you could notice the third input to the gates and it is fed to overcome switching issues.

What is T latch?

T latch:

It can be formed by using a shorted input to the JK Latch. Here, the letter ‘T’ stands for ‘Toggle’ as the output toggles based on the input.

What is a Flip Flop?

The flip-flops are built from latches and it includes an additional clock signal apart from the inputs used in the latches. It is capable of storing the binary values i.e. 0 or 1. As they are built from latches, we can again have four different types of flips flops based on the respective latches. So if you build it from an SR latch, then you would get an SR flip-flop by giving an additional clock signal to the latch. From the below, notice how the clock signal ‘C’ is sent as input to the JK flip-flop.

How do they work?

Latches work based on the input functions but flip flop work based on the clock signals. The timely output is the basic element that differentiates a flip-flop from a latch.

How are they triggered?

In latches, the binary inputs i.e. 0 or 1 play an important role in triggering the outputs. They can even be described as level-triggered as it reacts either in the level ‘0’ or in the level ‘1’. In flip-flops, the output gets triggered based on the ‘+ve’ or ‘-ve’ pulses of the clock. So it can better be described as edge triggered while considering when it reacts.

what is the difference between latches and flip flops?

	Latches	Flip Flops
What is it?	A Latch is a circuit element that alters the output based on the current input, previous input, and previous output.	The flip-flops are built from latches and it includes an additional clock signal apart from the inputs used in the latches.
Types	There are four types of latches namely SR Latch, D Latch, JK latch, and T Latch.	There are four types of flip flops namely SR Flip-flop, D Flip-flop, JK Flip-flop, and T Flip-flop.
Built From	They are built from logic gates to form sequential circuits.	They are built from latches with an additional clock signal to form sequential circuits.
Output changes	When there is a change in the input during the continuous input checking process	Of course, the outputs are computed based on the inputs during the continuous input checking process but they are computed only when the time signal is ‘+ve’.
Sensitive to?	It is sensitive to the input switch and we can transmit data as long as it is ‘On’.	It is sensitive to the clock signals and it never alters the output until there is a change in the input clock signal.
How do they work?	It works purely based on the binary inputs.	It works based on the binary inputs as well as on the clock signal.
Trigger Type	It is level triggered as the output gets changed based on the binary levels ‘0’ or ‘1’.	It works based on the binary inputs as well as on the clock signal.
Can be used as a register?	No. As registers need more sophisticated electronic circuits where time plays an important role. Here we miss the clock or time signals and hence it cannot be used as a register.	Yes. It includes clock signals in its inputs and therefore, cascaded flip-flops can be used as registers.
Synchronous?	No. It is asynchronous as it never works based on the time signals.	Yes. It is synchronous as it works based on the clock signals.

What are the applications of latches?

The basic purpose of a latch is to save the state of some particular input. The latches from today’s lecture are too simple to do much by themselves, but they can be used as part of more complicated circuits.

As an example from my own research: I might want to know which electronics channels fired when a particle went through my detector. I could design a circuit to latch the signals on each channel when a trigger condition was met, so that I could later read out the pattern of channels that fired.

There are lots of other applications for which one might want to save digital information. In general, latches and flip-flops are used to save the states of the bits that encode binary numbers (one wants one’s computer to remember the numbers it computes or it isn’t much use.

Applications of Flip Flops

Application of the flip flop circuit mainly involves in bounce elimination switch, data storage, data transfer, latch, registers, counters, frequency division, memory, etc. Some of them are discussed below.

Also see

How to Create a Test Bench for Verilog HDL Module?

Registers

A register is a collection of a set of flip flops used to store a set of bits. For instance, if you want to store an N – bit of words you need N number of FFS. AFF can store only one bit of data (0 or 1). A number of FFs are used when the number of data bits to be stored. A register is a set of FFs used to store binary data. The data storage capacity of a register is a set of bits of digital data that it can retain. Loading a register can be defined as setting or resetting the separate FFs, i.e, giving data into the register so the status of the FF communicates to the bits of data to be stored.

Data loading may be serial or parallel. In serial loading, the data is transferred into the register in the form of serial (i.e, one bit at a time), but in parallel loading, the data is transmitted into the register in the form of parallel form that means, all the FFs are activated into their new states at the same time. Parallel input necessitates that the SET or RESET controls of every FF to be accessible.

RAM (Random Access Memory)

RAM is used in computers, information processing systems, digital control systems it is necessary to store digital data and recover the data as preferred. FFS can be used to make memories in which information can be stored for any required length of time and then deliver whenever required.

The information stored in read-write memories built from semiconductor devices that will be lost if power is detached, that memory is said to be unstable. But read-only memory is non-volatile. RAM is the memory whose memory locations can be right to use directly and instantly. By contrast, to access a memory location on a magnetic tape, it is required to twist or untwist the tape and go through a series of addresses before reaching the preferred address. So, the tape is called the sequential access memory.