2020 21 1c

Computer Organization and Architecture2020-212 marksIEEE Standard for Floating Point Numbers

Discuss biasing with reference to floating point representation.

Discuss biasing with reference to floating point representation.

Biasing means adding a fixed constant, called the bias, to the true exponent before storing it. The stored value is then always a positive (unsigned) number, so no sign bit is needed for the exponent. It also lets us compare two floating point numbers using plain integer comparison.

In IEEE 754 single precision the bias is 127, so $E = e + 127$. In double precision the bias is 1023. For example, a true exponent of $-3$ is stored as $-3 + 127 = 124$, and a true exponent of $5$ is stored as $132$.

Short on time? The 1, 5 and 10 mark versions of this answer, flashcards and practice sets come with a program pass.

Up nextWhat is restoring method in division algorithm?