Understanding the CPU and the Fetch-Decode-Execute Cycle

The video tutorial introduces CPU City, a metaphor for the central processing unit (CPU), explaining how it executes the fetch-decode-execute cycle. It describes the roles of registers, buses, and the control unit in processing instructions. The fetch stage involves retrieving instructions from memory, the decode stage interprets these instructions, and the execute stage performs operations using the arithmetic logic unit. The tutorial illustrates this process with examples, highlighting how data is moved and processed within the CPU.

What is the primary function of registers in CPU City?

• To store data permanently

• To process arithmetic operations

• To manage the flow of information

• To connect different parts of the CPU

Which type of bus is responsible for carrying addresses in CPU City?

• Data bus

• Control bus

• Address bus

• Signal bus

Where does CPU City fetch instructions from?

• Control Unit

• Memory

• Arithmetic Logic Unit

• Registers

What is the role of the program counter in the fetch stage?

• To hold the address of the next instruction

• To store data temporarily

• To execute instructions

• To decode instructions

During the fetch stage, where is the instruction loaded after being copied from memory?

• Arithmetic Logic Unit

• Memory Data Register

• Control Unit

• Accumulator

What does the control unit do during the decode stage?

• Executes the instruction

• Fetches the next instruction

• Stores the instruction

• Decodes the instruction

What is the function of the accumulator in CPU City?

• To decode instructions

• To manage control signals

• To temporarily hold data for operations

• To store instructions permanently

In the execute stage, what happens to the data at memory location 3?

• It is sent to the arithmetic logic unit

• It is copied to the control unit

• It is discarded

• It is stored in the program counter

What does the instruction 'sub 4' mean in the context of CPU City?

• Multiply the value at location 4

• Store the value at location 4

• Subtract the value at location 4

• Add the value at location 4

What is the result of subtracting the value at location 4 from the value at location 3?

• 5

• 8

• 13

• 21