Important Digital Logic and Design Short Questions
Chapter: 26
Question 1:
What is a decade counter?
Answer:
A decade counter is a type of counter that counts ten unique states, from 0000 to 1001, and then resets to zero.
Chapter: 26
Question 2:
How can the 74LS93A IC be configured for different counting modes?
Answer:
The 74LS93A can be configured as a MOD-16 counter, Decade counter, or frequency divider by connecting its inputs and outputs appropriately.
Chapter: 26
Question 3:
What is the advantage of using integrated circuit counters like the 74LS93A?
Answer:
Integrated circuit counters like the 74LS93A simplify circuit design and provide reliable, compact solutions for counting and frequency division.
Chapter: 27
Question 4:
What is the main difference between an up-counter and a down-counter?
Answer:
An up-counter counts from zero to a maximum value and then resets, while a down-counter counts from a maximum value down to zero and then resets.
Chapter: 27
Question 5:
How is a down-counter implemented in terms of flip-flops?
Answer:
A down-counter is implemented by connecting the Q output of flip-flops to the clock inputs of the next flip-flops.
Chapter: 27
Question 6:
What is a truncated sequence in the context of a down-counter?
Answer:
A truncated sequence is when the down-counter counts from a maximum value to a predefined last count value, then resets to the maximum count value instead of going to zero.
Chapter: 27
Question 7:
How does a 3-bit down-counter handle a truncated sequence from 111 to 011?
Answer:
The counter counts down from 111 to 011, and when it reaches 011, it is preset to 111 instead of resetting to 000.
Chapter: 27
Question 8:
What is a key advantage of synchronous counters over asynchronous counters?
Answer:
Synchronous counters operate with a common clock signal, allowing all flip-flops to change state simultaneously, which reduces timing problems and supports higher frequency clocks.
Chapter: 27
Question 9:
What is the function of the AND gate in a 3-bit synchronous counter?
Answer:
The AND gate ensures that the third flip-flop toggles only when both of its inputs (F0 and F1) are at logic 1, helping to maintain the correct counting sequence.
Chapter: 27
Question 10:
Describe the clock transition effect in a 2-bit synchronous counter.
Answer:
On a clock transition, the first flip-flop toggles its output, which affects the second flip-flop after a propagation delay, leading to changes in both flip-flops' outputs.