It's typical in the data sheet descriptions to use the term latch for that circuit, which is an asynchronous circuit (not clocked) to differentiate if from a synchronous (clocked) latch which is referenced there as a flip-flip. I know that both types of devices can be called latches or flip-flops, but I think it simplifies the discussion and there usage if they are referred to by different labels.A flip-flop is a logic circuit that has two stable states, 0 and 1, or LOW and HIGH. This is also called a bi-stable.
This can be created by a digital gate using positive feedback. If the output is fed back to the input the input is reinforced by the output.
If the output is HIGH the input will be HIGH and will stay HIGH.
If the output is LOW the input will be LOW and will stay LOW.
This model uses a voltage model, not current, i.e. the LOW and HIGH levels refer to voltage levels.
The simplest flip-flop consists of two NOT gates wired in a loop, output of one gate connected to input of the other gate.
Here is a simple flip-flop using two NOT gates:
I agree -- as long as we don't get too in love with the notion that there is a rigid definition. Whenever we hear (or read) someone talking about a "latch" or a "flip flop" we should always do a sanity check and verify what is actually meant. The context usually allows this to be done easily and, with experience, the process becomes automatic and we don't even realize we are doing it.It's typical in the data sheet descriptions to use the term latch for that circuit, which is an asynchronous circuit (not clocked) to differentiate if from a synchronous (clocked) latch which is referenced there as a flip-flip. I know that both types of devices can be called latches or flip-flops, but I think it simplifies the discussion and there usage if they are referred to by different labels.
Disagree. Creating your own nomenclature for a device leads to no one knowing what you are talking about.It's typical in the data sheet descriptions to use the term latch for that circuit, which is an asynchronous circuit (not clocked) to differentiate if from a synchronous (clocked) latch which is referenced there as a flip-flip. I know that both types of devices can be called latches or flip-flops, but I think it simplifies the discussion and there usage if they are referred to by different labels.
I'm not creating my own nomenclature, I'm using what is commonly done in the industry. So you disagree that most data sheets use the term latch for the asynchronous circuit and flip-flop for the synchronous version?Disagree. Creating your own nomenclature for a device leads to no one knowing what you are talking about.
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You keep talking about with or without a clock. What do you think it should be called if it has a level-triggered clock input? Is this synchronous or asynchronous? Should it be called a latch, or a flip-flop?I'm not creating my own nomenclature, I'm using what is commonly done in the industry. So you disagree that most data sheets use the term latch for the asynchronous circuit and flip-flop for the synchronous version?
I rest my case.I'm not creating my own nomenclature, I'm using what is commonly done in the industry. So you disagree that most data sheets use the term latch for the asynchronous circuit and flip-flop for the synchronous version?
Notice that it ignores the case of the simple case of crosscoupled NAND or NOR gates. These don't have a clock at all and are called latches by some and flip-flops by others.Hello,
The following page was found in the internet archive:
http://web.archive.org/web/20100109...wichill.edu.bb/cmp/online/P10F/flip-flops.htm
It shows you a couple of flip-flop types.
Bertus
As well as most engineering textbooks. There is a clar distinction in digital circuit design. Latches are usually avioded and reported by design rules checking software. No so for flip flops.All I'm saying is that the data sheets for common CMOS and TTL circuits (as far as I've seen) use the term FF for clocked bistable elements and latch for async bistable elements.