ALU 101 Carry and Overflow 2

Question 1

Overflow in signed binary arithmetic occurs when:

Accepted Answer

The result cannot be represented in the given number of bits

Answer

Overflow occurs when the arithmetic result exceeds the range representable by the assigned number of bits in signed arithmetic.

Question 2

What does the ALU's carry flag (C flag) indicate?

Accepted Answer

An unsigned carry-out or borrow from the most significant bit

Answer

The carry flag is set when there is a carry-out (addition) or borrow (subtraction) from the most significant bit in unsigned operations.

Question 3

Can overflow and carry both be set at the same time in a single ALU addition?

Accepted Answer

Yes, they can occur independently

Answer

Carry and overflow are independent flags: carry relates to unsigned results exceeding bit width, while overflow relates to signed result range violation.

Question 4

Adding two positive signed numbers yields a negative result. This is an example of:

Accepted Answer

Signed overflow

Answer

When adding two positive numbers produces a negative result in signed arithmetic, it is a signed overflow because the result exceeded the positive range.

Question 5

In 4-bit two's complement, what is the result of 0111 + 0001?

Accepted Answer

1000 with overflow

Answer

0111 + 0001 = 1000 in binary; in 4-bit two's complement, 1000 = −8, so adding 7+1 overflowed the positive range.

ALU 101 - Arithmetic Logic Unit 101 Exam Practice Test

ALU 101 - Arithmetic Logic Unit 101 Exam Practice Test

ALU 101 Carry and Overflow 2