Deck 21: Microprogrammed Control

Question 1

A microprogram consists of a sequence of instructions in a microprogramming language.

Answer 1

True

Question 2

It is easier to design in hardware than in firmware.

Answer 2

False

Question 3

The _________ contains the address of the next microinstruction to be read.

A)control memory
B)control address register
C)control word
D)control buffer register

Answer 3

B

Question 4

The advantage of horizontal microinstructions is that they are more compact than vertical microinstructions,at the expense of a small additional amount of logic and time delay.

Question 5

The control unit design is very flexible.

Question 6

It is important to design compact,time-efficient techniques for microinstruction branching.

Question 7

The principal advantage of the use of microprogramming to implement a control unit is that it simplifies the design of the control unit.

Question 8

The TI 8800 Software Development Board is a microprogrammable 32-bit computer card.

Question 9

The degree of packing relates to the degree of identification between a given control task and specific microinstruction bits.

Question 10

The PDP-11 is the first member of the LSI-11 family that was offered as a single board processor.

Question 11

Microprogramming became a popular technique for implementing the control unit of CISC processors.

Question 12

The set of microinstructions is stored in the __________.

A)control address register
B)control buffer register
C)control memory
D)control word

Question 13

To implement a control unit as an interconnection of basic logic elements is a very simple task.

Question 14

It is more difficult to write a firmware program than a software program.

Question 15

Which of the following is a control unit input?

A)IR
B)ALU flags
C)clock
D)all of the above

Question 16

When a microinstruction is read from the control memory it is transferred to a _________.

A)control buffer register
B)control memory
C)control address register
D)control unit

Question 17

A microprogram is midway between hardware and software.

Question 18

The principal disadvantage of a microprogrammed unit is that it will be somewhat slower than a hardwired unit of comparable technology.

Question 19

Reading a microinstruction from the control memory is the same as executing that microinstruction.

Question 20

The term microprogram was first coined by __________ in the early 1950s.

A)M.V.Wilkes
B)D.Siewiorek
C)M.Sebern
D)S.Tucker

Question 21

The terms __________ relate to the relative width of microinstructions.

A)packed / unpacked
B)hard / soft
C)horizontal / vertical
D)direct / indirect

Question 22

An alternative,which has been used in many CISC processors,is to implement a __________ control unit.

Question 23

With _________ encoding one field is used to determine the interpretation of another field.

A)resource
B)indirect
C)direct
D)functional

Question 24

The _________ is a 32-bit ALU with 64 registers that can be configured to operate as four 8-bit ALUs,two 16-bit ALUs,or a single 32-bit ALU.

A)PDP-11
B)8832
C)3033
D)8818

Question 25

The standard IBM 3033 control memory consists of ________ words.

A)2K
B)8K
C)4K
D)16K

Question 26

In a __________ microinstruction every bit in the control field attaches to a control line.

Question 27

_________ processors,with their simpler instruction format,typically use hardwired control units.

Question 28

Each line of a microprogramming language describes a set of micro-operations occurring at one time and is known as a ________.

Question 29

A sequence of instructions is known as a ___________,or firmware.

Question 30

Which of the following is a LSI-11 microinstruction?

A)add word
B)test word
C)Jump
D)all of the above

Question 31

The two basic tasks performed by a microprogrammed control unit are microinstruction sequencing and microinstruction __________.

Question 32

The __________ generated by a microinstruction are used to cause register transfers and ALU operations.

Question 33

_________ is a subfield that is used to indicate a conditional branch.

A)ZERION
B)S2-S0
C)SELDR
D)OSEL

Question 34

A ________________ instruction depends on the following types of information: ALU flags,part of the opcode or address mode fields of the machine instruction; parts of a selected register -- such as the sign bit,and status bits within the control unit.

Question 35

The _________ allows multiple levels of nested calls or interrupts and it can be used to support branching and looping.

A)stack
B)register
C)counter
D)firmware

Question 36

In a ________ microinstruction a code is used for each action to be performed and the decoder translates this code into individual control signals.

Question 37

Microprogramming is the dominant technique for implementing control units in pure _________ architectures due to its ease of implementation.

Question 38

In executing a microprogram the address of the next microinstruction to be executed is in which of the following categories?

A)determined by instruction register
B)branch
C)next sequential address
D)all of the above

Question 39

A _________ is a combinatorial circuit that generates an address based on the microinstruction,the machine instruction,the microinstruction program counter,and an interrupt register.

A)microsequencer
B)vertical microinstruction
C)translation array
D)control word

Question 40

The terms _________ microprogramming are used to suggest the degree of closeness to the underlying control signals and hardware layout.

A)hard / soft
B)horizontal / vertical
C)direct / indirect
D)packed / unpacked

Question 41

Each microinstruction cycle is made up of two parts: fetch and _________.

Question 42

The LSI-11 is a good example of a __________ microinstruction approach.

Question 43

The principal function of the 8818 __________ is to generate the next microinstruction address for the microprogram.

Question 44

Two approaches can be taken to organizing the encoded microinstruction into fields: functional and __________.

Question 45

The __________ approach involves the use of a microinstruction address that has previously been saved in temporary storage within the control unit.