Midterm 2 - Chapter 4 Terms

Question 1

Define ALU

Answer 1

Arithmetic Logic Unit - The device that performs the arithmetic operations like addition and subtraction or logical operations like AND and OR. (8)

Question 2

Define BUS

Answer 2

Collection of data lines that is treated together as a single logical signal; also a shared collection of lines with multiple sources and uses. (11)

Question 3

What are Multiplexers?

Answer 3

a selector, since its output is one of the inputs that is selected by a control. (12)

Question 4

What are the Logic Design Basics?

Answer 4

• Information encoded in binary
• Combinational element
• State sequential elements (15)

Question 5

What is clocking methodology?

Answer 5

Combinational logic transforms data during clock cycles. (20)

Question 6

What does a datapath consist of?

Answer 6

• registers
• ALUs
• mux’s
• memories
• Elements that process data and addresses in the CPU * (21)

Question 7

What is op?

Answer 7

It is an operation code or opcode that selects a specific operation. (24)

Question 8

What is rs and rt?

Answer 8

First and second source registers (24)

Question 9

What is rd?

Answer 9

destination register (24)

Question 10

What is shamt?

Answer 10

“shift amount” used only for shift instructions (24)

Question 11

What is func?

Answer 11

It is used together with op to select and arithmetic instruction. (24)

Question 12

R-Format Instructions

Answer 12

• Read two register operands
• Perform arithmetic/logical operation
• Write register result (25)

Question 13

What do branch instructions do?

Answer 13

• Read register operands
• Compare operands
• Calculate target address (29)

Question 14

What does the Load instruction do?

Answer 14

Read memory and update register (26)

Question 15

What does the Store instruction do?

Answer 15

Write register value to memory (26)

Question 16

Five Stages of MIPS Pipeline are _______.

Answer 16

• IF: Instruction fetch from memory
• ID: Instruction decode & register read
• EX: Execute operation or calculate address
• MEM: Access memory operand
• WB: Write result back to register (43)

Question 17

What is speed up?

Answer 17

1 / (1 - instruction count change) * (cycle time without / cycle time with)