Design a Controlled 4-bit Comparator circuit using Logisim.
Design a 4-bit comparator based on the following specifications:
Inputs: Two 4 bit numbers A = A3A2A1A0 and B =B3B2B1B0
1-bit control C where: If C = 0, then A and B are unsigned binary numbers.
If C = 1, then A and B are 2’s complement signed numbers.
1-bit control C where: If C = 0, then A and B are unsigned binary numbers.
If C = 1, then A and B are 2’s complement signed numbers.
Outputs:
Computerized or Double Comparators are made up from standard AND, NOR and NOT entryways that think about the advanced signs introduce at their information terminals and deliver a yield contingent on the state of those sources of info.
For instance, alongside having the capacity to include and subtract double numbers we should have the capacity to think about them and decide if the estimation of info An is more prominent than, littler than or equivalent to the incentive at input B and so on. The advanced comparator achieves this utilizing a few rationale doors that work on the standards of Boolean Variable based math. There are two main types of Digital Comparator available and these are.
- 1. Identity Comparator – an Identity Comparator is a digital comparator with only one output terminal for when A = B, either A = B = 1 (HIGH) or A = B = 0(LOW)
- 2. Magnitude Comparator – a Magnitude Comparator is a digital comparator which has three output terminals, one each for equality, A = B greater than, A > B and less than A < B
The reason for an Advanced Comparator is to look at an arrangement of factors or obscure numbers, for instance, An (A1, A2, A3, … . An, and so forth) against that of steady or obscure esteem, for example, B (B1, B2, B3, … . Bn, and so on) and deliver a yield condition or banner relying on the aftereffect of the examination. For instance, a greatness comparator of two 1-bits, (An and B) sources of info would create the accompanying three yield conditions when contrasted with each other.
A>B or A=B or A<B
Which means: A is greater than B, A is equal to B, or A is less than B
This is helpful on the off chance that we need to contrast two factors and need to deliver a yield when any of the over three conditions are accomplished. For instance, create a yield from a counter when a specific check number is come to.
The image provides a 4-bit unsigned comparator. On the same basis, we can design signed comparator. If you need further explanation and original logisim files please email at shivamtyagi18@gmail.com.