What does this pattern represent in IEEE 754 ?

Question

11111111111000000000000000000000

(no.1=11, no.0=21)

Answer 1

The 8-bit exponent field is all one-bits, so it's not a normal number. It's either minus infinity, or a representation of "Not-a-Number". Visit the web site to learn more.

Answer 2

The IEEE Standard for Binary Floating-Point Arithmetic (IEEE 754) is the most widely-used standard for floating-point computation, and is followed by many CPU and FPU implementations. The standard defines formats for representing floating-point numbers (including negative zero and denormal numbers) and special values (infinities and NaNs) together with a set of floating-point operations that operate on these values. It also specifies four rounding modes and five exceptions (including when the exceptions occur, and what happens when they do occur).

Answer 3

first bit is the sign bit
8 bits of biased exponent
remainder of bits is magnitude