# Write the bit pattern for the decimal value

#### lamentofking

Assuming a three-bit exponent field and a four-bit significand, write the bit pattern for the following decimal values:

(a) -12.5 (b) 13.0 (c) 0.43 (d) 0.1015625

Here are the answers I got for each:

(a) 1 110 1010

(b) 1 110 1010

(c) 0 001 1011

(d) 0 000 1101

I don't know how to check if these are correct. Could someone help me please?

#### chiro

MHF Helper
Hey lamentofking.

Are these IEEE values (or derivatives)? Do you have the definition of the floating point number as a function of the exponent, significand, and sign bit?

1 person

#### lamentofking

Hey lamentofking.

Are these IEEE values (or derivatives)? Do you have the definition of the floating point number as a function of the exponent, significand, and sign bit?
I don't know how to tell. These problems come from the Computer Systems by Warford textbook. Any the problem is before IEEE is covered so I would say no. These are floating point numbers. The sign bit is the first number, the next three numbers are the exponent, and the significand is the last four numbers.

#### chiro

MHF Helper
It sounds like it is a quasi-IEEE (in other words, not a standard float or double, but a representation that has the same form only with the number of bits different).

Anyway, I can't really help you unless you have the formula to convert the representation to a decimal number (or a number in another base).

The only other suggestion I have is to see if its a fixed point representation. Fixed point is just a way of storing a number with so many possibilities for the integer value and so many possibilities for the non-integer value. Based on what you have said about the structure of the number, I don't think its a fixed point representation.

Take a look at this and see if it has a connection:

IEEE floating point - Wikipedia, the free encyclopedia