To convert a Gray Code to its binary equivalent, which technique is commonly…
2025
To convert a Gray Code to its binary equivalent, which technique is commonly used?
- A.
Subtraction method
- B.
Addition method
- C.
Exclusive OR (XOR) operation
- D.
Division method
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Correct answer: C
To convert a Gray code to its binary equivalent, the most commonly used technique is the successive Exclusive-OR (XOR) logic operation.
This technique can be performed manually using an algorithm or implemented in hardware using a chain of XOR gates.
1. The Manual Conversion Algorithm
When converting an n-bit Gray code (Gn-1 ..... G1 . G0 ) to a binary number (Bn-1 ..... B1 . B0 ), follow these steps from left to right (Most Significant Bit to Least Significant Bit):
Keep the MSB the same: The first binary bit (Bn-1) is exactly equal to the first Gray code bit (Gn-1).
XOR diagonally: To find the next binary bit, perform an XOR operation between the previous calculated binary bit and the current Gray code bit.
Repeat this process for all remaining bits.
Mathematical Formula:
Bn-1 = Gn-1
Bi = Bi+1 ⊕ Gi (where ⊕ represents the XOR operation)
2. A Practical Example (Convert Gray 1011 to Binary)
Let’s convert the 4-bit Gray code 1011 into its binary equivalent:
Bit 3 (MSB): Keep it the same.
B3 = G3 = 1
Bit 2: XOR the previous binary bit (B3) with the current Gray bit (G2).
B2 = B3 ⊕ G2 = 1 ⊕ 0 = 1
Bit 1: XOR the previous binary bit (B2) with the current Gray bit (G1).
B1 = B2 ⊕ G1 = 1 ⊕ 1 = 0
Bit 0 (LSB): XOR the previous binary bit (B1) with the current Gray bit (G0).
B0 = B1 ⊕ G0 = 0 ⊕ 1 = 1
Result: The Gray code 1011 is equal to binary 1101.
3. Hardware Circuit Implementation
In digital electronics, this algorithm is implemented using a cascaded chain of XOR gates. The output of each XOR gate feeds into the input of the next gate down the line.
Core Concept Reminder for MCQs
Gray to Binary: Uses the previously generated binary bit to XOR with the next Gray bit (Cascaded/Serial dependency).
Binary to Gray: Uses adjacent binary bits (Bi ⊕ B i+1) to generate the Gray code (Parallel operations, no dependency on previous results).