Computer Architecture Flashcards
What is the Stored Program Concept?
Machine code instructions stored in main memory are fetched and executed serially by a processor that performs arithmetic and logical operations
What’s the function of the ALU and what does it stand for
The Arithmetic Logic Unit performs arithmetic and logical operations.
What are examples of functions the ALU performs?
Performs functions such as:
- Fixed and floating point arithmetic
- Logical operations (AND, OR, XOR)
- Shift operations
- ADD, DIVIDE, SUBTRACT, MULTIPLY
Where are the inputs from and the outputs of the ALU ?
Inputs are from the accumulator
Outputs are routed to one of the registers.
What is the function of the Control Unit?
- Directs data flow between the cpu and other devices
- fetches program instructions from memory, to decode them and to execute them serially.
What is the function of the system Clock?
The clock synchronises all computer operations by sending a signal to each of the computer components on a regular basis.
What is a register?
A register is fast temporary storage that exists in the processor or I/O controller.
What are the two types of registers?
General purpose and dedicated registers
What are General Purpose registers used for?
- Usually named R0-R15
- They are used to hold instructions and data temporarily.
- All arithmetic/logical/shift operations takes place in the general purpose registers
What are special purpose/dedicated registers used for, name the 6 main ones?
They are used by the processor to carry out a specific role.
- PC, Program Counter
- ACC, Accumulator
- MAR, Memory Address Register
- MBR, Memory Buffer Register
- CIR, Current register
- SR, Status Register
What is Von Neumann Architecture?
Is when both instructions and data are stored in the same memory and share the same buses
What is Harvard Architecture?
is when data and instructions are stored in seperate memories and are accessed using different buses
When is Von Neumann Architecture mostly used?
- Used for general use computers
- helpful for running a variety of programs simultaneously
When is Harvard Architecture mostly used?
Used in embedded systems and situations where the speed of an operation is important
Name the internal components of a computer system?
- Processor
- Main memory
- address bus, control bus, data bus
- I/O controllers
What is the role of the processor?
To execute program instructions in order to run applications
What does the processor contain?
The control unit, the ALU and registers
What is a bus?
A set of parallel wires connecting two or more components of a computer
What is an i/o controller?
- A device which receives input/output requests from the processor and sends device specific control signals to the device they control
- They manage data flow to and from the device
What are the 3 parts that make up a i/o controller
- An interface connecting the controller to the system bus
- A set of data/command/status registers
- An interface connecting the controller to the cable connecting the device to the computer
Give an example of an interface
A USB
What is an advantage of using Harvard architecture
Can be faster as data and instructions can be fetched in parallel instead of having to compete for the same bus
How many general purpose registers does a computer typically have?
16
What is the accumulator?
A general purpose register
