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Normally, for any counter, we can use both PET (Positive edge triggering) or NET (Negative edge triggering). But, most of the time we use NET. The reason is that in case of PET, considering a standard asynchronous counter ( n-bit), the output of nth flip-flop will change it's state, as it's preceding flip-flop changes it's state from 0 to 1 or low to high. In general, we take the output of flip-flop from Q input, and, the counter will seem to run in reverse order, if PET is used.
This can be understood by an example. Let us take a 2-bit counter with PET J-K Flip-Flops. Let the clock input is applied to the first Flip-Flop. Now taking a look at it's states. Assume that, initially all the flip-flops are at logic low. At the first rising edge of the clock pulse, FF0 (First flip-flop) will change it's state from 0 to 1. This transition from 0 to 1 by FF0 is the clock input to FF1, which sees a rising edge at it's clock input, will also change it's state from 0 to 1. So, at the first clock pulse, the counter will go from it's initial state of 00 to 11. On, second clock pulse, FF0 will transit from 1 to 0, but FF1 will remain at 1 because it is seeing a falling edge. So, the state will shift from 11 to 10. At third pulse, FF0 will shift from 0 to 1, and FF1 will shift from 1 to 0. so, the state will shift from 10 to 01. Finally, at fourth clock pulse, FF0 will shift it's state from 1 to 0 and, FF1 will remain at it's previous state. so, the new state will be 00. Now, taking a look at complete cycle we will have, 00,11,10,01....... so on. So, it is clear that counter is behaving as down counter or reverse counter.
It is a general practice to take output from Q output and not from Q-bar (~Q). So, a better method is to use NET. Since, the output of FF1 in that case will shift it's state when FF0 will shift from 1 to 0. So, the state cycle in that case will be, 00,01,10,11..... so on. It is clear that output of FF1 is changing only when FF0 is changing from 1 to 0 ie. falling edge.
So, to conclude, we can say that in general, we use negative edge triggering in case of counters.
What else can I help you with?
What are the application of flip flop?
This flip-flop toggles (Q changes state) on the negative going edge of the clock pulse. T acts as an ENABLE / INHIBIT control. Q will only toggle on the negative edge of the clock pulse, when T is high. Below is shown a D type flip-flop connected as a toggle type. On each clock pulse positive going edge, Q will go to the state bar Q was before the clock pulse arrived. Remember that bar Q is the opposite level to Q. Therefore Q will toggle.
Level triggered and edge triggered advantages and disadvantages?
Level Trigger:1) The input signal is sampled when the clock signal is either HIGH or LOW.2) It is sensitive to Glitches.Example: Latch.Edge Trigger:1) The input signal is sampled at the RISING EDGE or FALLING EDGE of the clock signal.2) It is not-sensitive to Glitches.Example: Flipflop.
Which flip flops are used in counter?
In counters, the most commonly used flip-flops are the D flip-flop and the T (toggle) flip-flop. The D flip-flop is often used in synchronous counters where data is sampled on a clock edge, while the T flip-flop is particularly suited for binary counters because it toggles its output state with each clock pulse. Both types enable the construction of various counting sequences in digital circuits.
What are the uses of counters to logic circuits?
counters are used to store, display or sometimes count the pulses in a circuit.
What type of indent would you use to move the left edge of a paragraph to the left of the left margin?
negative indent
Is there a difference between edge triggering and pulse triggering?
Yes, there is a difference between edge triggering and pulse triggering. Edge triggering occurs when a circuit changes state based on the transition of an input signal (e.g., from low to high or high to low). Pulse triggering, on the other hand, involves triggering a circuit based on the detection of a specific pulse width within the input signal.
What do you mean by edge triggered flip flop and pulse triggered flip flop?
An edge-triggered flip-flop changes states either at the positive edge (rising edge) or at the negative edge (falling edge) of the clock pulse on the control input.
What is a flip flop and latch?
flipflop is edge triggering and latch is level triggering
Do negative counters have the ability to eliminate creatures with indestructible?
No, negative counters do not have the ability to eliminate creatures with indestructible.
What is your balance if you have the same number of positive and negative counters?
Zero.
Why negative edge triggering is preferred?
Negative edge triggering is often preferred in digital circuits because it allows for more reliable and stable clock signal transitions. It helps to minimize the effects of noise and glitches that may occur during the high state of a clock signal, reducing the risk of unintended state changes. Additionally, many flip-flops and other digital components are designed to respond to negative edges, which can lead to more efficient synchronization in timing-critical applications. This characteristic can improve overall circuit performance and reliability in complex digital systems.
What type of central locking is in citroen saxo?
negative triggering relay.
Characteristiccs of UJT?
The characteristics of a UJT are: stable triggering voltage, negative resistance, high pulse current capability and low value of triggering current.
Does Dijkstra's algorithm work for graphs with negative edge weights?
No, Dijkstra's algorithm does not work for graphs with negative edge weights because it assumes all edge weights are non-negative.
How does Dijkstra's algorithm handle negative edge weights in a graph?
Dijkstra's algorithm does not work with negative edge weights in a graph because it assumes all edge weights are non-negative. Negative edge weights can cause the algorithm to give incorrect results or get stuck in an infinite loop. To handle negative edge weights, a different algorithm like Bellman-Ford should be used.
Why the digital circuits are edge triggered?
Not all are: JK flip-flops use a master-slave triggering for example.
What are the application of flip flop?
This flip-flop toggles (Q changes state) on the negative going edge of the clock pulse. T acts as an ENABLE / INHIBIT control. Q will only toggle on the negative edge of the clock pulse, when T is high. Below is shown a D type flip-flop connected as a toggle type. On each clock pulse positive going edge, Q will go to the state bar Q was before the clock pulse arrived. Remember that bar Q is the opposite level to Q. Therefore Q will toggle.
