High Level Architecture Flashcards
To learn computer parts
1
Q
What does a computer consist of?
A
- Central Processing Unit (CPU)
- System Clock
- Primary Clock (RAM)
- Secondary Memory (HDD)
- Peripheral input and output devices (keyboard & mouse)
- Bus (Parallel wires to connect everything)
2
Q
What does the CPU do?
A
- is the “brain” of the computer
- Executes instructions
- Controls the transfer of data across the bus
3
Q
What 3 main parts does a CPU consist of?
A
- Control Unit (CU)
- Arithmetic Logic Unit (ALU)
- Registers
4
Q
What does the Control Unit do?
A
- Directs execution from instructions by loading an operation code (opcode) from primary memory into the Instruction Register
- Decodes opcode to identify the operation
- If needed, transfers data between primary registers and memory
- If needed, directs ALU to operate on data in registers
5
Q
What does the ALU do?
A
- Preforms arithmetic and logical operations on data stored in registers
- Examples include adding numbers stored in 2 source registers and storing them in a third, destination register or using 2 source registers for bitwise AND
6
Q
What are registers?
A
- Binary storage units within the CPU
- May contain data, addresses, Instructions and Status Info
- Examples: General purpose registers to hold data and addresses
- Program Counter (PC) register contains the address in memory of the currently executing instruction, is incremented to execute next instruction
- Status Register(SR) contains information(flags) about the result of a previous instruction
7
Q
How does the System Clock work?
A
- Generates a clock signal to synchronize the CPU and other clocked devices by using a square wave at a particular frequency. Devices are synched using the rising or falling edges of the wave.
- Example 2016 iMac has 3.2GHz
8
Q
What is primary memory?
A
- Often called RAM
- Any byte in Memory can be directly accessed if you know its address
- Can be written to and read from
- Is said to be volatile (data disappears when powered off)
- Is used to store program instructions and data(variables)
- Consists of a sequence of addressable memory locations
- Each location is typically one byte long
- von Neumann Architecture contains both data and programs (instructions)
- Harvard Architecture uses separate memories for data and programs
Example Sizes: iMac 2016 8GB
9
Q
What do busses do?
A
- Is a set of parallel data/signal lines
- Is used to transfer information between computer components
- Often subdivided into address, data and control boxes
10
Q
What does the Address Bus do?
A
- Specifies a memory location in RAM or sometimes a memory - mapped I/O device
- basically specifies where to transfer data
- common sizes are 32 and 64 bit
11
Q
What does the Data Bus do?
A
- Used for bidirectional data transfer between locations in the architecture
- Common sizes 23 and 64 bytes per bit
12
Q
What does the Control bus do?
A
- Used to control or monitor devices connected to the bus
- this manages the information flow between components indicating whether the operation is a read or a write and ensuring that the operation happens at the right time.
13
Q
What does secondary memory do?
A
- Is used to hold a computer’s file system (stores files containing programs or data)
- Is non-volatile read/write memory (Its contents persist through a power cycle)
- Usually embodied on a hard disk drive(HDD)
14
Q
What do peripheral I/O devices do?
A
- Allow communication between the computer and the external environment
- Input examples: joystick, mic, scanner
- Output examples: speakers, printers
- I/O examples: Modem, connections to networks
15
Q
How does accumulator-based architecture work?
A
- Register for short term, intermediate storage of arithmetic and logic data in a computer’s CPU
- accumulator can be loaded from or stored to RAM
- Operands for an instruction come from the accumulator and a single location in RAM
- ALU results are always stored in ACC
