## What is synchronous up and down counter?

Synchronous Up/Down Counter (JK flipflops) A synchronous 4-bit up/down counter built from JK flipflops. Depending on the logic value on the Up/nDown input, the counter will increment or decrement its value on the falling edge of the clock signal.

### Which flip-flop is used in synchronous counter?

Synchronous Counters use edge-triggered flip-flops that change states on either the “positive-edge” (rising edge) or the “negative-edge” (falling edge) of the clock pulse on the control input resulting in one single count when the clock input changes state.

What is a synchronous up counter?

Definition: The synchronous counter is a type of counter in which the clock signal is simultaneously provided to each flip-flop present in the counter circuit. More specifically, we can say that each flip-flop is triggered in synchronism with the clock input.

Which flip-flops are used in synchronous and asynchronous counter?

1. In synchronous counter, all flip flops are triggered with same clock simultaneously. In asynchronous counter, different flip flops are triggered with different clock, not simultaneously. 2.

## What is the T flip-flop?

The T flip-flop is also called toggle flip-flop. It is a change of the JK flip-flop. The T flip flop is received by relating both inputs of a JK flip-flop. The T flip-flop is received by relating the inputs ‘J’ and ‘K’. When T = 0, both AND gates are disabled.

### What is difference between asynchronous up and down counter?

The only difference is that for the up counter the output is taken at the non-inverting output ports of the flip-flops. Whereas, for the down counter, the output is taken at the inverting output ports of the flip-flops.

What is up down counter?

An up-down counter is a combination of an up-counter and a down-counter. It can count in both directions, increasing as well as decreasing. Depending on the type of clock inputs, counters are of two types: asynchronous counters and synchronous counters.

What is synchronous flip-flop?

In a synchronous circuit, flip-flops are used as the basic memory element, a typical example being the JKFF. Unlike latches, they only respond to a transition on a clock input or to a change in an asynchronous input such as Clear.

## What is D and T flip-flop?

D Flip-Flop: When the clock rises from 0 to 1, the value remembered by the flip-flop becomes the value of the D input (Data) at that instant. T Flip-Flop: When the clock rises from 0 to 1, the value remembered by the flip-flop either toggles or remains the same depending on whether the T input (Toggle) is 1 or 0.

### What is the truth table of T flip-flop?

T Flip Flop Truth Table

T Qn
0 0 Unchanged/hold
0 1 Unchanged/hold
1 0 Toggle
1 1 Toggle

What is difference between synchronous & asynchronous counters?

1. In the synchronous counter there are continuous clock input signals with flip-flops used to produce the output. In Asynchronous counters there are different clock signals used to produce the output. 2.

What is asynchronous down counter?

In the asynchronous counter, an external clock pulse is provided for only the first flip flop, thereafter the output of the 1st FF acts as a clock pulse for the second FF and so on. In the case of synchronous FFs, all the flip flops are triggered simultaneously by an external clock pulse.