Question

What is a two complements overflow, what is a signed overflow, what is an unsigned overflow, what is a carry and what is a borrow. Please feel free to use your own examples. Thank you very much.

Answer 1

Two 's complement overflow

If 2 Two's Complement numbers are added, (both positive or both negative), then overflow occurs . Overflow does not occur when adding numbers withdifferent signs.

Signed overflow

Signed overflow occurs when two signed 2's complement numbers are added, overflow is detected if:

1.both operands A and B positive and the result is negative.
2.both operands A and B negative then the result is positive.

For example 100

+100

----------

1000

-----------

In this example both are positive, overflow occured because result cannot be expressed in 3 bits.

Carry:carry occurs while adding two numbers.

It is the digit added to other column more significant digit.for example, while adding 5 and 7 result is 12 .2 is written in same column and 1 is carried to other column.

In subtraction it is called borrow

Borrow: borrow occurs when subtracting two binary numbers