5.1 - Internal Computer Architecture Flashcards
What is a computer system?
Any device that can take a set of inputs and process them into useful outputs
What are the components of the computer base unit?
- processor
- main memory (RAM)
- address, control, data buses
- input/output controllers
What are I/O controllers?
Pieces of hardware that control the communication of data between the processor and external hardware devices such as keyboards, mics and monitors
What are device drivers?
Software that interacts directly with the I/O controller
When you install a new device the device driver must be installed on it
How does an I/O controller work?
- converts the signals received from a peripheral device into the format the computer can process, and vice versa
- received I/O requests from the CPU and then sends device specific control signals to the device it is controlling
- manages the data flow to and from the device, freeing the CPU to get on with other tasks
What is the control bus used for?
Used to carry control signals that regulate the operation of the computer system
Also carries the computers clock signal
What does the data bus do?
Sends data and instructions to and from the different components in the computer system
What does the address bus do?
Transports memory addresses specifying where data is to be sent to or retrieved from
What are the different types of control signals?
Memory read: causes data from the addressed location to be placed in the data bus
Memory write: causes data on the data bus to be written into the addressed location
Bus request: indicates that a device is requesting use of the data bus
Bus grant: indicates the CPU has granted access to the use of the data bus
Clock: used to synchronise operations
What is a bus?
A series of parallel wires that connects internal components of a computer system allowing signals to be passed between them
What are words?
Memory that is divided up into equal units
Usually 8, 16, 32 or 64 bits
Each word has a separate memory address
What direction is the data bus?
Bi-directional - data can be sent both ways along the bus
How is the width of the data bus defined? How does this affect words?
Number of parallel wires or lines it contains
If data bus is the same width as a computer word, data can be transferred in a single operation
What direction is the address bus?
One directional - carries addresses of a memory location from the processor to I/O controllers and memory
What does the width of the address bus determine?
Maximum possible memory addresses of the system
32-bit bus can carry 2^32 memory addresses
