GATE Overflow Test Series | Digital Logic | Test 1 | Question: 14

Question

Which of the following is/are special values in IEEE-754 single precision representation?

1. All mantissa bits $0s$
2. All exponent bits $1s$
3. All exponent bits $0s$
4. All mantissa bits $1s$
5. Both mantissa and exponent bits all $0s$
6. Both mantissa and exponent bits all $1s$

 

• A. 1 and 4 only
• B. 1, 4, 5 and 6 only
• C. 2, 3, 5 and 6 only
• D. 5 and 6 only

Answer 1

In IEEE-754 representation, special values are represented with all $0s$ or all $1s$ in the exponent field.

• Denormalized: Exponent is all $0s.$ Used to extend the range of smallest positive as well as largest negative number that can be represented.
• ZERO: Both mantissa and exponent are all $0s.$ There are two zero values corresponding to the $2$ sgin values but they both compare equal.
• Infinity: Exponent is all $1s$ and mantissa is all $0s.$
• Not a Number: Used to represent not a real number. It has exponent all $1s$ and a non zero mantissa.