fetch-decode

Question 1

fetch phase

Answer 1

address from the program counter is copied to the memory address register

instruction held at the address is copied to memory data register, simultaneously ,the contents of the program counter are increased by 1

-contents of the mdr are copied to the current instruction register

Question 2

decode phase

Answer 2

-contents of cir are split into operand and opcode

Question 3

execute phase

Answer 3

The decoded instruction is executed