Unit 2 Flashcards
Describe the key characteristics and types of primary memory
(Direct Access) Primary memory is computer memory accessed directly by the CPU.
(SPEED) Because Primary memory is accessed directly by the CPU, it is faster to access than secondary memory/storage.
(TYPES) Primary Memory includes Random Access Memory (RAM), processor cache e.g Level 1 or Level 2 cache and Read only memory (ROM) although typically primary memory refers to RAM
Outline one function of the ALU
Arithmetic Logic Unit (ALU) is a part of processor that performs arithmetic and logical operations.
Outline how a colour can be represented in a computer.
A colour will be split into three components (Accept RGB as an Example);
Each component will be assigned a certain number of bytes.
Describe the function of the Control Unit (CU) in the Central Processing Unit (CPU)
Obtains the data/instructions from the memory;
Interprets and decodes them into commands/steps/signals;
Controls Transfer of data and instructions among other units of a CPU (For Example, command to ALU for execution);
Manages/Coordinates all the units of the computer
State the Purpose of Cache Memory and Explain why the cache memory can speed up the proccessing within a computer.
Cache Memory can be accessed/is faster than RAM
It is used to hold common/Expected/frequently used data or operations.
It is closer to CPU than RAM, situated between RAM and CPU/on same board as CPU/with faster read/write speed.
Cache memory is Static Memory and this memory doesn’t need to be constantly refreshed
Define the term Bit
Binary Digit;
(Minimal) unit of storage that can be set to 0 or 1
Outline the relationship between Binary and Hexadecimal number
Binary Number have base 2, hexadecimal numbers have base 16 (2^4=16); Each digit (letter/number) is a hexadecimal number can be represented by the group of 4 binary digits.
In a 8 but register, state the binary representation of the Hexadecimal number 3B.
8 4 2 1 8 4 2 1
2^3 2^2 2^1 2^0 2^3 2^3 2^1 2^0
0 0 1 1 1 0 1 1
One of the functions of an operating system is memory management. Describe how this function prevents the system from crashing when more than one program is running at the same time.
The OS allocates and de-allocates specific sections of memory to each programs. This ensures the memory assigned to one program is not overwritten;
It uses secondary/virtual memory to allow more processes to run simultaneously
What is machine instruction cycle?
The machine instruction cycle is the process by which a program instruction is fetched, decoded, executed and the results are stored. All the instructions and data are stored in primary memory/ram.
Busses are used as a physical connection to carry information to the CPU;
The data bus transports data from/to cpu whereas the address bus the memory address where data us supposed to go/be.
Outline the role of memory data register in the machine execution cycle.
Memory Data register Holds (a copy of) the contents of the memory; which are to be transferred from/to memory to/from other CPU components.
Allowing the processor and memory to act independently/processor not affected by differences in the speed of operations.
