Stevens Institute Of Technology

CS 550

Chapter 7 The CPU And Memory

1)The Little Man instruction set is based on a decimal number system; real computers encode instructions and data using the

1. 1. binary system.
   2. Unicode system.
   3. decimal system.
   4. algebraic system.

 

2. The ALU and CU together are known as the
   1. CPU.
   2. instruction set.
   3. program counter.
   4. Memory Management Unit.

 

3. The area inside of the CPU that holds data temporarily and performs calculations is called the
   1. accumulator.
   2. program counter.
   3. arithmetic logic unit.
   4. Memory Management Unit.

 

4. The storage locations that are used for a particular defined purpose within the CPU are called
   1. RAM.
   2. storage.
   3. the bus.
   4. registers.

 

5. The 1-bit registers that are used to allow the computer to keep track of special conditions (like overflow or power failure) are often called
   1. flags.
   2. loops.
   3. the ALU.
   4. I/O counters.

 

6. Loading the value zero into a register is called
   1. inverting a register.
   2. clearing a register.
   3. dumping the register.
   4. incrementing a register.

 

7. The register that holds the address of the memory location that needs to be accessed is called the
   1. IR.
   2. MAR.
   3. MDR.
   4. MBR.

 

8. The register that holds the current instruction is called the
   1. IR.
   2. PC.
   3. LMC.
   4. MBR.

 

9. The register that will hold the data value that is being transferred between the CPU and a particular memory location is called the
   1. PC.
   2. ALU.
   3. MAR.
   4. MDR.

 

10. The mailboxes in the LMC model are the equivalent to a real computer's

1. CPU.
2. ports.
3. memory.
4. control unit.

 

11. Which of the following is NOT one of the three lines that control the memory cell?

1. Skew line
2. Address line
3. Read/write line
4. Activation line

 

12. If the Memory address register is 8 bits wide, the number of possible memory addresses is

1. 8
2. 16
3. 64

d) 256

 

13. Memory that retains its values when power is removed is called

1. DRAM.
2. SRAM.
3. volatile.
4. nonvolatile.

 

14. There would never be a reason for an address transfer from the                  to another register within the CPU.

1. IR
2. PC
3. MAR
4. MDR

 

15. When the instruction being executed is to store data, the data will be transferred from another register in the CPU to the , and from there it will be transferred into memory.

1. IR
2. PC
3. MAR
4. MDR

 

16. The different ways of establishing memory addresses within an instruction are called

1. MAR codes.
2. MDR codes.
3. addressing modes.
4. programmable modes.

 

17. Flash Memory

1. is volatile.
2. is faster than standard RAM.
3. has unlimited rewrite capacity.
4. is nonvolatile.

 

18. The first step in the instruction cycle is

1. clear the accumulator.
2. fetch the instruction from memory.
3. decode the instruction in the accumulator.
4. copy the data from the MAR to the MDR.

 

19. The physical connections that make it possible to transfer data from one location in the computer system to another are called

1. flags.
2. fibers.
3. buses.
4. peripherals.

 

20. Optical conductors are

1. faster than electrical conductors.
2. cheaper than electrical conductors.
3. more common than electrical conductors.
4. all of the above.

 

21. A bus in which there is an individual line for each bit of data, address, and control is called a

1. wide bus.
2. serial bus.
3. parallel bus.
4. dedicated bus.

 

22. A bus that transfers data sequentially, one bit at a time using just a single line pair is called

1. a serial bus.
2. a single bus.
3. a narrow bus.
4. a sequential bus.

 

23. A bus line that is "one-way" is called

1. a simplex bus line.
2. a serial bus line.
3. a one-way bus line.
4. a sequential bus line.

 

24. A bus line that can carry data in both directions at the same time is called a

1. simplex bus line.
2. complex bus line.
3. full duplex bus line.
4. half duplex bus line.

 

25. The exposed connectors into which external cables can be plugged are often called

1. plugs.
2. lines.
3. ports.
4. stacks.

 

26. A bus that carries signals from a single specific source to a single specific destination is a(n)

1. simplex bus.
2. broadcast bus.
3. Ethernet bus.
4. point-to-point bus.

 

27. Virtually every bus internal to the CPU is

1. serial.
2. cables.
3. optical.
4. parallel.

 

28. Instructions that only the operating system can execute are called

1. system instructions.
2. executive instructions.
3. privileged instructions.
4. administrative instructions.

 

29. Programs that execute without privileges are said to execute

1. in user space.
2. in data mode.
3. in kernel space.
4. in privilege space.

 

30. Multimedia applications, like modifying an image, often use

1. PSW instructions.
2. Flash instructions.
3. MMD instructions.
4. SIMD instructions.

 

31. The sources and destinations of data for an instruction are known as

1. Op codes.
2. Operands.
3. Op registers.
4. Operation fields.

 

32. Increasing the number of bits available for the op code in an instruction word

1. increases the demand on the CPU.
2. increases the number of memory locations that can be addressed.
3. increases the number of instructions available in the instruction set.
4. has no impact on any of the above. Discussion Questions
   1. How are the registers in the CPU different from main memory?

 

 

1. 2. How does the computer keep track of special conditions such as arithmetic carry and overflow, power failure, and internal computer error?

 

 

1. 3. What factor factor determines the maximum capacity of memory in a real computer?

 

 

1. 4. Why is it necessary to store start-up program code in nonvolatile memory?

 

 

1. 5. Why is flash memory not suitable for use as main memory?

 

 

1. 6. Classify the registers as either a) holding addresses only, b) holding instructions only, or c) anything.

 

IR                                 

PC MAR MDR

Accumulator                     

General Purpose             

 

 

1. 7. What is the technique that real computers use to extend the address space beyond that of the address field in an instruction?

 

 

1. 8. What is skew?

 

1. 9. What are “Arithmetic Shifts” commonly used for?

 

1. 10. Explain pop and push operations on a stack.

 

 

1. 11. Why are input/output instructions generally considered privileged instructions?

 

 

 

1. 12. What are different ways of characterizing a bus? In other words, what attributes do all buses have?

 

 

 

1. 13. Why is there no need for a subtract instruction?

 

 

 

1. 14. Identify the implicit and explicit addresses in the Little Man instruction 531; recall that “5” is the op code for the load instruction.

 

 

1. 15. What is an important disadvantage of variable length instructions?