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?

  1. A.

    Subtraction method

  2. B.

    Addition method

  3. C.

    Exclusive OR (XOR) operation

  4. 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):

  1. Keep the MSB the same: The first binary bit (Bn-1) is exactly equal to the first Gray code bit (Gn-1).

  2. XOR diagonally: To find the next binary bit, perform an XOR operation between the previous calculated binary bit and the current Gray code bit.

  3. 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).

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