Question

Discussion Topic: In a program written in a high level language, if an arithmetic error occurs the program aborts and produces an error message that usually has the phrase "Arithmetic Overflow Error". This can happen in different circumstances such as: an illegal calculation was performed, such as trying to divide a number by zero the result of a calculation is a number that is too large or two small for the computer to store and in other circumstances as well. Which ALU flag do you think is responsible for indicating that an arithmetic overflow has occurred? Briefly state the ALU flag you think is responsible and briefly state your reasoning for believing that flag indicates when a high level program had an arithmetic overflow error.

Answer 1

Solution:

Arithmetic overflow errors are the errors that are occured when we perform any arithmetic operations like addition, subtraction, multiplication, division, bitwise operations. One of the good examples is dividing number by zero

Overflow generally means if the bits exceeded the allocated space. Generally the overflow can be a carry bit.

ALU generally by its name Arithmetic and Logical Unit takes care of all the arithmetic and logical operations that are performed in the program.

ALU has two types of flags. Carry Flag and Overflow flag.

The overflow flag is used for signed numbers and carry flag is used for unsigned numbers.

ALU does not care whether it is performing math on signed or unsigned numbers. It simply uses flags to determine the signed or unsigned numbers. So there is a sign flag.

So we cannot tell whether it is carry flag or overflow flag that causes Arithmetic overflow error. For signed numbers, the overflow flag is on which is repsonsible for the error.

For unsigned numbers, the carry flag is on which is repsonsible for the error.