go to previous page   go to home page   go to next page hear noise


The exponent.

The Exponent

IEEE754 format

The eight bits 23 through 30 contain the exponent. The exponent is an integer, but may be negative, zero, or positive. You might guess that an 8-bit two's complement integer would work perfectly for this, but a different type of notation is used.

The exponent is expressed using a biased integer. The true exponent is added to +12710 resulting in an unsigned binary integer. The biased integer is encoded using 8-bit unsigned binary.

Exceptions: (1) A floating point value of 0.0 is represented with a mantissa of 23 zero bits and an exponent of 8 zero bits. It is not legal to have an exponent of zero with a non-zero mantissa. (2) The exponent 25510 (1111 1111) is used to signal various problems, such as division by zero.


What is the mantissa when the entire float is zero?