BCD Code: Representing Decimal Digits with 4 Binary Digits

The question asks for a digital code where each decimal digit is represented using exactly 4 binary digits. This specific type of representation is characteristic of the Binary Coded Decimal (BCD) code.

Understanding Binary Coded Decimal (BCD)

BCD is a standard method for representing decimal numbers in binary form. Unlike converting the entire decimal number to its standard binary equivalent, BCD encodes each decimal digit (0 through 9) independently using a 4-bit binary pattern.

• Each decimal digit requires 4 bits.
• The patterns used for digits 0-9 are the standard binary representations of those numbers.

BCD Conversion Examples

Here's how the decimal digits 0 to 9 are represented in BCD:

Why Other Codes Don't Fit

• Binary Code: This is a general term for representing data using binary digits (0s and 1s). While BCD uses binary, the term "binary code" doesn't specifically imply the 4-bit representation for *each* decimal digit. Standard binary conversion of numbers like 10 would be 1010, not two separate 4-bit codes.
• ASCII Code: ASCII (American Standard Code for Information Interchange) is used to represent text characters (letters, numbers, symbols, control characters). It typically uses 7 or 8 bits per character, not 4 bits per decimal digit.
• Gray Code: Gray code is a binary numeral system where successive values differ by only one bit. It's used in applications like error correction or position encoders, not specifically for encoding decimal digits in a 4-bit format.

Therefore, BCD is the digital code where each decimal digit is represented by 4 binary digits.