Components of a CPU

Question 1

ALU

Answer 1

Arithmetic Logic Unit - Handles the arithmetic and logic calculations. Can calculate Boolean decisions, also.

Question 2

PC

Answer 2

Program Counter - stores the address of the next instruction to be executed. If a branch is encountered, the instruction stored is sent to a stack

Question 3

ACC

Answer 3

Accumulator - Stores the results of the ALU or any data held in the MDR

Question 4

MDR

Answer 4

Memory Data Register - Used to temporarily store data read from or to the memory

Question 5

MAR

Answer 5

Memory Address Register - Stores the address of where data is to be fetched from or to write to

Question 6

CIR

Answer 6

Current Instruction Register - Holds the current instruction being executed, split into operand and opcode

Question 7

Data Bus

Answer 7

Moves data between the memory and processor, bidirectional movement

Question 8

Address Bus

Answer 8

Divides the memory into “words” and each word has an address. The “words” are 16, 32, or 64 bits of data. Unidirectional bus from CPU to memory.

Question 9

Control Bus

Answer 9

command such as: ensure access to and use of data is granted, write data, synchronize actions, request access.
Sometimes unidirectional, bidirectional if microprocessor needs to know bus transactions