1.1.1 OCR CS A-Level

What does the program counter hold?

• The current instruction

• The address of the next instruction

• The data to be processed

• The result of the last operation

What is the role of the memory address register?

• To store the result of the operation

• To hold the address to be accessed in memory

• To store the current instruction

• To hold the address of the next instruction

What signal does the control unit send to read data from memory?

• Write signal

• Fetch signal

• Decode signal

• Read signal

What is stored in the current instruction register?

• The address of the next instruction

• The data to be processed

• The current instruction

• The result of the last operation

What are the two parts of an instruction?

• Control and Data

• Address and Data

• Fetch and Decode

• Opcode and Operand

What does the opcode represent?

• The result of the operation

• The operation to be performed

• The address of the next instruction

• The data to be processed

What is the role of the accumulator in the CPU?

• To store the current instruction

• To decode instructions

• To store intermediate results/ results from the ALU

• To hold the address of the next instruction

What does the instruction 'branch always' do?

• Increments the program counter

• Replaces the program counter with a new address

• Stores data in memory

• Outputs data to the user

What happens after an instruction is fetched from memory in the FDE Cycle?

• The instruction is stored permanently

• The instruction is executed

• The instruction is decoded

• The program counter is decremented

What is transferred to the MDR (Memory Data Register) during the execution of a program?

• The data to be processed

• The address of the next instruction

• The instruction itself

• The result of the computation