4.5 - Fundamntals of data representation Flashcards
What is the use of natural numbers?
Counting Items.
What is the use of real numbers?
Measuring things.
Why is hexadecimal used?
Useful for representing binary numbers but being easier to read and understand.
What are unsigned binary numbers?
Unsigned binary represent positive numbers, where the maximum value for n digits is (2^n) -1
What is two’s complement?
A way of representing negative numbers, where the largest bit is represented as a negative number.
How to convert from unsigned binary to a negative number?
Flip all the bits in the binary number, and add 1.
How is audio converted from analogue to digital?
Samples of the audio taken at regular intervals. Amplitude at each sample is measured. Data is coded into binary.
What is an advantage of floating point?
It can represent much larger numbers than fixed point.
What is an advantage of fixed point?
It can represent some numbers more accurately than floating point in a given number of bits.
How to convert from floating point representation to decimal?
Calculate the value of the mantissa and exponent. Then mantissa * 2^exponent.
What are the advantages of Harvard architecture?
Instructions and data can be accessed simultaneously. Different technologies can be used to implement data and instruction memory.
What are check digits?
An extra bit is added on the end of a packet to check the accuracy of the data. Used to recognise and prevent human errors when entering or assigning identification numbers
What is majority voting?
Each bit is sent an odd number of times, when they arrive the most common for each bit is taken as the final.
What are parity bits?
The number of 1s in the data is counted. Then an extra bit is added to the start or end to make the number of 1s either even or odd depending on the parity.
