Digital Systems T3

Question 1

Assuming enough resources (2-input AND gates) are available, ALL partial products (PPs) are calculated

Answer 1

Concurrently

Question 2

In a binary multiplication, which bits of the final product are calculated first?

Answer 2

The LSbits

Question 3

Binary multiplication can be implemented in custom hardware (HW) or software (SW)

Answer 3

True

Question 4

When is the value of the PP zero?

Answer 4

When the associated multiplier bit is 0

Question 5

The most time-consuming operation in a binary multiplication is

Answer 5

The multi-operand addition of the PPs

Question 6

In the SSRM discussed in class, PH-Reg is initiated to

Answer 6

0

Question 7

in the SSRM discussed in class, the M-reg stores the value

Answer 7

Of the original multiplicand

Question 8

In the SSRM described in class, a new PP is generated using

Answer 8

2-to-1 muxes

Question 9

In the SSRM discussed in class, which sequence of operations are repeated?

Answer 9

Add shift-right

Question 10

The SSRM mPL-Reg is used to store

Answer 10

The remaining bits of the multiplier and the incoming LSbits of the FP

Question 11

The behavioral description of the SSRM SU uses if-else and/or case constructions. which of the following is NOT used in the condition evaluations of these constructs

Answer 11

DONE

Question 12

The SSRM CST captures ONLY sequential events

Answer 12

False

Question 13

Why is it necessary to use external control inputs START?

Answer 13

So that the SSRM knows when a new set of input operands is valid and ready to be multiplied

Question 14

If the Multiplicand is n-bits wide and the multiplier is m-bits where how many times does the add-shift sequence repeat in the SSRM

Answer 14

m

Question 15

In the lecture SSRM ASM chart we initialized n = 4 and counted down to 0. We would initialize n = 0, and we would need to

Answer 15

Count up to 4

Question 16

How many different data sets can the PSRM be described in the class process concurrently?

Answer 16

4

Question 17

The PSRM improves

Answer 17

Throughput

Question 18

In each stage of the PSRM which operations are executed during every machine cycle

Answer 18

Add and shift right

Question 19

In each PSRM stage, the PP is generated

Answer 19

using 2-input AND gates

Question 20

On average, division takes longer than multiplication

Answer 20

True

Question 21

The generate function indicates that a carry-out of ‘1’ will be generated by stage:

Answer 21

No matter what the carry-in value is

Question 22

Compared to the RCA, a CLA uses:

Answer 22

More hardware resources

Question 23

What is the RCA’s biggest performance problem?

Answer 23

The propitiation of carry values form one stage to the next

Question 24

How many gate-level propagation delays are there in a generic SUM-Of-Producs (SOP)?

Answer 24

2

Question 25

The propagate function p = ‘1’ the the carry-out value will be ‘1’ if:

Answer 25

The carry value is ‘1’

Question 26

At the cost of additional and acceptable propagation delay, the second level carry-look-ahead reuses computation results in the form of

Answer 26

Gj, and Pj

Question 27

In an attempt to trade odd code/performance, we can combine carry look-ahead and ripple-carry in the same adder unit

Answer 27

True

Question 28

What is a practical limit for the number of inputs to a (static) CMOS gate?

Answer 28

4

Question 29

How many gate-level propagation delays does it take to compute the sum of a stage in a RCA or CLA from the moment the cin to the stage is available

Answer 29

1

Question 30

Comparing a n-bit CLA to a n-bit RCA:

Answer 30

The CLA is faster, bit uses significantly more hardware resources

Question 31

In a positional number system, the position of a digit:

Answer 31

Represents the weight it carries

Question 32

To convert a number to an IEEE floating point format, the number is first normalized. the integer part of the normalized value:

Answer 32

Is not stored, but implied when the value of the number is being reconstructed

Question 33

In the IEEE floating formats, the stored exponent is stored in an excess form. this means that the actual exponent value is equal to:

Answer 33

The stored exponent value minus the excess value

Question 34

To be able to use floating point numbers in manipulation, these have to be:

Answer 34

Unpacked -> Manipulated -> Packed

Question 35

In a weighted number system, the value of a number is equal to:

Answer 35

The SUM of the PRODUCTS between each digit vale and the radix(or base) raised to the power of its position

Question 36

Which representation covers a wider range of numbers?

Answer 36

Floating-Point

Question 37

When the exponent = 111…1 and the fraction = 000…0 the number is interpreted as:

Answer 37

± infinity

Question 38

The value 0 is represented by

Answer 38

Exponent = 0 and fraction (stored mantissa) = 0

Question 39

When two floating point numbers are multiplied

Answer 39

The (1+ mantissas) are multiplied, and the exponents added

Question 40

For addition and subtraction, the mantissas of floating point numbers

Answer 40

Have to be aligned