3.1.4. Examples of Arithmetic Operations

Try these first

1. 1.

   What flag indicates that the result of an operation is zero?

   Hint

   Think about when you add numbers that balance out.

2. 2.

   If 5 + 4 equals 9, is there an overflow in unsigned arithmetic?

   Hint

   Consider the maximum you can represent in your bits.

3. 3.

   What indicates an overflow in signed arithmetic?

   • Carry Flag
   • Overflow Flag
   • Zero Flag

   Hint

   Think about which flags relate to signed numbers.

4. 4.

   True or False: An overflow occurs when two large numbers are added together and exceed the maximum representable value.

   • True
   • False

   Hint

   Consider what it means to go beyond the limits of your representation.

5. 5.

   Calculate the result of -2 + 5 and determine if there’s an overflow. If the result is represented in 4-bits, what does it yield?

   Hint

   Convert to binary and examine the range.

6. 6.

   If two large negative numbers are added and produce a positive result in a signed integer operation, what has happened? Analyze the results within a 4-bit system.

   Hint

   Employ binary addition to illustrate.