4.5.4 FoDR - Binary Number System Flashcards
What is the difference between unsigned and signed binary
- Unsigned binary can only be used to represent Natural numbers, Whereas signed binary is used to represent Integer numbers
What is the minimum value that can be represented in unsigned binary with n bits
0
What is the maximum value that can be represented in unsigned binary with n bits
2ⁿ-1
What is meant by an overflow
Where the result of an operation has more bits than there are available
What is meant by an underflow
Where the result of an operation has less bits than there are available
What is the range for the number of numbers that you can represent using the Two’s complement
-2ⁿ –> 2ⁿ⁻¹-1
How many numbers can be represented using twos complement
2ⁿ
What are the advantages of Fixed Point
- Simpler to calculate therefore the process is generally faster
What are the advantages of Floating Point
- Has a larger range for the same number of bits
What are the characteristics of Floating Point Binary
- Uses Mantissa and Exponent
- Precision depends on the number of bits used to represent the mantissa
- Range depends on the number of bits used to represent th eexponent
What are the characteristics of Fixed Point Binary
- The range depends on how close the binary point is to the LSB
- The precision depends on how close the binary point is to the MSB
Why can both representation of fractional binary be inaccurate
Some numbers can just not be represented exactly in binary, this means it can only be an approximation e.g. 0.1, which can cause rounding errors
How do you round a binary number
- Look at the first bit that you cannot store
- If its a 1, add 1 to the whole number, then truncate the number
- If 0, truncate the number
What are the conditions for binary number to be normalised
- If positive: 0.1
- If negative: 1.0
What is the condition for a real number to be represented in a binary number system
Its fractional part must be able to be represented exactly in binary
What is meant by the absolute error
The difference between the approximation and the true value
What is the equation for the absolute error
A = difference between true value and approximation
What is meant by the relative error
A measure of the uncertainty in a given value compared to the true value
What is the equation for relative error
Relative Error = Absolute Error/ Actual Value