What is 4-bit decade counter?
A 4 bit binary counter will act as decade counter by skipping any six outputs out of the 16 (24) outputs. There are some available ICs for decade counters which we can readily use in our circuit, like 74LS90. It is an asynchronous decade counter. The above figure shows a decade counter constructed with JK flip flop.
What is 4-bit asynchronous up counter?
Asynchronous 4-bit UP counter. A 4 bit asynchronous UP counter with D flip flop is shown in above diagram. It is capable of counting numbers from 0 to 15. The clock inputs of all flip flops are cascaded and the D input (DATA input) of each flip flop is connected to a state output of the flip flop.
What is asynchronous decade counter?
Asynchronous Decade Counter This type of asynchronous counter counts upwards on each trailing edge of the input clock signal starting from 0000 until it reaches an output 1001 (decimal 9). Both outputs QA and QD are now equal to logic “1”. We now have a decade or Modulo-10 up-counter.
How many different states does 4-bit asynchronous counter have?
Explanation: In a n-bit counter, the total number of states = 2n. Therefore, in a 4-bit counter, the total number of states = 24 = 16 states.
How does a 4-bit counter work?
A 4-bit Synchronous up counter start to count from 0 (0000 in binary) and increment or count upwards to 15 (1111 in binary) and then start new counting cycle by getting reset. Its operating frequency is much higher than the same range Asynchronous counter.
Which one is a 4-bit binary ripple counter *?
Which one is a 4-bit binary ripple counter? Explanation: IC 7493 is a 4-bit binary ripple counter. It is a MOD-16 counter with 24 = 16 states. Explanation: IC 7493 consist of 4 J-K master-slave flip-flop.
How 4 bits up counter works explain?
Normally the counter increments the 4 bit word (Q4,Q3,Q2,Q1) by one every time the clock input is toggled. If the UP/DOWN input is asserted the counter counts down (subtracts one) upon each clock cycle instead. The CARRY OUT and CARRY IN signals are used when more than one counter are used “in cascade”.
How many FFs are required for 4-bit up down counter?
In a 4-bit up-down counter, there are 4 J-K flip-flops required. For modulus-10 counter, N = 10. Therefore, 23 < = 10 < = 24. Thus, n = 4, and therefore, we require 4 FFs.
What is a decade counter?
A decade counter is one that counts in decimal digits, rather than binary. A decade counter may have each (that is, it may count in binary-coded decimal, as the 7490 integrated circuit did) or other binary encodings. A decade counter is a binary counter that is designed to count to 1001 (decimal 9).
How many flip flops are needed for a 4-bit counter?
4 Flip Flops
This means that to design a 4-bit counter we need 4 Flip Flops. The counter also has a reset pin that enables it to enter an all-zero state i.e. the output of the counter is ‘0’ if the reset is ‘1’ irrespective of the clock and the current state of the flip flops.
What is the difference between a synchronous and an asynchronous 4-bit counter?
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.
How does an asynchronous 4 bit up counter work?
In the asynchronous 4- bit up counter, the flip flops are connected in toggle mode, so when the when the clock input is connected to first flip flop FF0, then its output after one clock pulse will become 20. The rising edge of the Q output of each flip flop triggers the clock input of its next flip flop.
What are the outputs of a decade counter?
As it is a 4 bit binary decade counter, it has 4 output ports QA, QB, QC and QD. When the count reaches 10, the binary output is reset to 0 (0000), every time and another pulse starts at pin number 9. The Mod of the IC 7490 is set by changing the RESET pins R1, R2, R3, R4.
What are the different types of asynchronous counters?
Different types of Asynchronous counters 1 4 bit synchronous UP counter 2 4 bit synchronous DOWN counter 3 4 bit synchronous UP / DOWN counter More
Why are asynchronous decade counters used in low power applications?
For high clock frequencies, counting errors may occur, due to propagation delay. Asynchronous counters are used as frequency dividers, as divide by N counters. These are used for low power applications and low noise emission. These are used in designing asynchronous decade counter.