Structure and role of the processor and it's component Flashcards
What does the Arithmetic Logic Unit do?
Performs arithmetic and logical operations
What is the purpose of the Control Unit?
Supervises the fetch-decode-execute cycle, sends/receives control signals and decodes each instruction once it has been fetched from memory
What is the purpose of the clock?
To generate timing signals
What does a general purpose register store?
Any data
What is a dedicated register?
A register dedicated to holding specific data for a specific purpose
What is the purpose of the program counter?
Store the address of the next instruction.
What is the purpose of the current instruction register?
Stores the instruction currently being executed
What is the purpose if the memory address register?
Stores the data address of the item in memory being addressed. Could refer to instruction or data
What is the purpose of the Memory buffer register?
Stores data currently being fetched from memory
What is the purpose of the status register?
Stores the current state of the processor, such as whether an overflow has occurred
Describe the fetch part of the fetch-decode-execute cycle.
The clock tick starts cycle
The contents of the PC are copied to the MAR
PC is incremented by 1
Address bus transfers contents of MAR to memory
The data at that memory location is transferred to the processor via the data bus
The fetched data is stored in the MBR
The data is transferred to the CIR
Describe the decode part of the fetch-decode-execute cycle.
The data in the CIR is split into opcode and operand
Describe the execute part of the fetch-decode-execute cycle if data needs to be fetched from memory.
Address of data is stored in MAR
Address bus transfers contents of MAR to main memory
Data at that memory location is transferred to the processor via the data bus
Fetched data stored in MBR
What is an opcode?
An operation code that describes the operation that is to be performed
What is an operand?
The value in which the operation is to be carried out
