The Processor Flashcards
What is the ALU responsible for?
Performing arithmetic calculations and logical operations that include:
Addition, subtraction, multiplication, division
Logical bitwise operations, such as AND, OR, NOT, and XOR
Comparisons between values, such as greater than, less than, equal to
Shifting binary patterns to the left or right
What is the main purpose of the control unit?
Organising the sequence in which program instructions are executed, followed by decoding the instructions.
What tasks are the control unit responsible for?
It uses control signals to enable data to be read (i.e. loaded) from and written (i.e. stored) to the main memory
It decodes every instruction that the processor will execute to determine what needs to be done
It organises the sequence of micro-operations that need to be performed in order to carry out an instruction
It uses control signals to determine the operation the ALU will carry out at each instance
What is the clock?
The clock generates regular clock pulses by emitting a signal that continuously oscillates between a low (or ‘0’) and a high (or ‘1’) state. The clock signal is used to synchronise the operations of the processor components
What are the five registers?
Accumulator
Memory Data Register (MBR)
Memory Address Register (MAR)
Program Counter (PC)
Current Instruction Register (CIR)
What is the purpose of the Program Counter (PC)?
Holds the address of the next instruction to be executed by the processor.
What is the purpose of the Current Instruction Register (CIR)?
Holds the current instruction that the processor is executing.
What is the purpose of the Memory Address Register (MAR)?
Temporarily holds the address of the memory location (in main memory) that the processor needs to access, either to read from (i.e. load data) or write (i.e. store data) to.
What is the purpose of the Memory Data Register (MDR)?
Temporarily holds the data (data values or instructions) that are read from or written to the main memory.
