QUESTION 9:
How many different values is it possible to represent using our 8-bit fixed point representation?
| Power of 2 | 3 | 2 | 1 | 0 | . | -2 | -3 | -4 | -5 |
|---|---|---|---|---|---|---|---|---|---|
| Decimal | 8 | 4 | 2 | 1 | . | 0.5 | 0.25 | 0.125 | 0.0625 |
| Include? | 0 | 1 | 1 | 1 | . | 1 | 1 | 0 | 1 |
= 4 + 2 + 1 + 0.5 + 0.25 + 0.0625 = 7.8125
The binary addition algorithm works for our eight-bit fixed point notation! In early computers and calculators this enabled the same circuits to be used for integer arithmetic (both signed and unsigned) and for fixed point arithmetic. This looks very promising.
However, fixed point is not as useful as the floating point representation which has replaced it. Floating point will be discussed in the next chapter.
How many different values is it possible to represent using our 8-bit fixed point representation?