FIT1047 Week 4

A CPU (in Von Neumann architecture) consists of:

• CPU, memory, and input/output

• ALU, control unit, and registers

• ALU, control unit, and memory

• Fetching, decoding, and executing

In a CPU, the control unit is connected to:

• ALU

• Registers

• Memory

• All three

What is the difference between registers and memory?

• Registers are faster than memory

• The registers contain the code to be run, and the memory contains all the data stored on the computer

• Registers have less storage size than memory

• Registers are used to store temporary values whereas memory stores data and code

What is the difference between a simple adder and a full adder?

What is the difference between general-purpose and special-purpose registers?

Match the following MARIE registers with their purpose

• Stores temporary values

• PC

• Stores the memory address to be read form/written to

• MAR

• Stores the value read from/written to memory

• AC

• Stores the current instruction

• IR

• Stores the address of the next instruction

• MBR

The output of a combinational circuit​ (a)   , whereas the output of a sequential circuit ​​ (b)   .

• depends only on the current inputs
• depends on the sequence of inputs over time
• depends on the sequence of circuits before it
• depends on how quick the clock speed is
• depends on how often it is used

What does the control unit in a CPU do?

• Lets the user control the CPU with a keyboard and mouse

• Fetches, decodes, and executes code

• Controls and coordinates the ALU, memory, and registers

• Stores the code that will be run by the CPU

Match the following types of code with their definition/purpose

• Highly readable code that is easy to write

• Register transfer language

• Mnemonic-based code that maps directly onto machine code

• Assembly language

• Binary code that defines CPU instructions

• Machine code

• Code used by the control unit to transfer data within the CPU

• High-level language

Reorder the Fetch step in RTL

• MAR <- PC

• PC <- PC + 1

• MBR <- M[MAR]

• IR <- MBR

Answer explanation

for each of these steps, what would happen if it wasn't run?