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The components of a computer - Coggle Diagram
The components of a computer
Motherboard
memory chip
expansion slots
CPU
Arithmetic and Logic Unit (ALU)
Control unit (CU)
Registers
General Purpose registers
Function
●
Load data from main memory into a register
●
Store data temtextporarily in arithmetic
● Store data from a register into main memory.
Example
Base register (BX)
Counter (CX)
Accumulator(AX)
Data register (DX)
Status Registers
Function
● Contain a number of flag bits indicating the status after the execution of instructions
● Used in instructions of conditional testing and program branching
Control Register
Function
●Contain the instructions to be executed by the CPUs
● Contains the memory address of the next instruction to be executed
●Facilitate the communication of the CPU with the main memory through the system bus.
Example
Instruction Register (IR)
Program Counter (PC)
Memory Address Register (MAR)
Memory Data Register (MDR)
peripherals
output peripherals
device
Printer, scanner, monitor
Storage peripherals
device
USB flash drive
Communication peripherals
device
Broadband modem
input peripherals
device
Monitor, keyboard, mouse, microphone, scanner, digital video camera
System Bus (Bus line)
Address bus
Transfer the source address or the destination address of data.
Control bus
Indicate the direction of the data transfer and coordinate the timing of the event during transfer.
Data bus
Transfer data and instructions.
Size of a bus = bus width
determines the number of bits of data the computer can transmit at one time
Machine Cycle
Process of executing an instruction in a CPU
Decode
Identify the operation code and operands in an instruction.
Execute
Interpret the operation code and perform the required operation.
fetch
Read the next instruction from the main memory into the instruction register (IR).
Main Memory
random access memory
Temporarily hold the data and instructions of application software and the operation system
Volatile = all data stored in RAM disappears instantly after the computer is turned off
Access time is just a hundredth of hard disk
Read-only Memory(ROM)
Store the permanent information supplied by the manufacturer
Contain the bootstrap program which loads and initializes the operation system of the computer.