Digital Logic Design Lecture 2

Index

Why Binary?

Computers use binary because it simplifies the hardware. Electrical circuits can easily represent two states: on (1) and off (0). These states correspond to binary digits. Additionally, binary arithmetic is simpler than decimal arithmetic, making computations more efficient.

Conversion Methods

Binary to Decimal

  • Integer:

    • Each binary digit (bit) represents a power of 2.
    • Multiply each bit by its corresponding power of 2.
    • Add the results.

    Example: 1011 = 1*2^3 + 0*2^2 + 1*2^1 + 1*2^0 = 8 + 0 + 2 + 1 = 11

  • Fractional:

    • Each binary digit after the decimal point represents a negative power of 2.
    • Multiply each bit by its corresponding negative power of 2.
    • Add the results.

    Example: 0.110 = 1*2^-1 + 1*2^-2 + 0*2^-3 = 0.5 + 0.25 + 0 = 0.75

Decimal to Binary

  • Integer:

    • Continuously divide the decimal number by 2.
    • The remainders form the binary equivalent from right to left.

    Example: Convert 13 to binary:

    • 13 / 2 = 6, remainder 1
    • 6 / 2 = 3, remainder 0
    • 3 / 2 = 1, remainder 1
    • 1 / 2 = 0, remainder 1
    • Binary equivalent: 1101
  • Fractional:

    • Continuously multiply the fractional part by 2.
    • The integer part of the result becomes the next binary digit.
    • Repeat until the fractional part becomes 0 or the desired precision is reached.

    Example: Convert 0.625 to binary:

    • 0.625 * 2 = 1.25 Integer part: 1
    • 0.25 * 2 = 0.5 Integer part: 0
    • 0.5 * 2 = 1.0 Integer part: 1
    • Binary equivalent: 0.101