Microprocessor - Multiple Choice Questions

Multiple Choice
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#1. The minimum number of transistors required to implement a two input AND gate is

a. 2

b. 4

c. 6

d. 8

Answer: c

2. Using DeMorgan's Theorem we can convert any AND-OR structure into

a. NAND-NAND

b. OR-NAND

c. NAND-NOR

d. NOR-NAND

Answer: a

3. For a memory with a 16-bit address space, the addressability is

a. 16 bits

b. 8 bits

c. 2^16 bits

d. Cannot be determined

Answer: d

4. Because we wish to allow each ASCII code to occupy one location in memory, most memories are _____ addressable.

a. BYTE

b. NIBBLE

c. WORD (16 bits)

d. DOUBLEWORD (32 bits)

Answer: a

5. Circuit A is a 1-bit adder; circuit B is a 1 bit multiplier.

a. Circuit A has more gates than circuit B

b. Circuit B has more gates than circuit A

c. Circuit A has the same number of gates as circuit B

(Hint: Construct the truth table for the adder and the multiplier)

Answer: a

6. When the write enable input is not asserted, the gated D latch ______ its output.

a. can not change

b. clears

c. sets

d. complements

Answer: a

7.  A structure that stores a number of bits taken "together as a unit" is a

a. gate

b. mux

c. decoder

d. register

Answer: d

8. We say that a set of gates is logically complete if we can build any circuit without using any other kind of gates.  Which of the following sets are logically complete

a. set of {AND,OR}

b. set of {EXOR, NOT}

c. set of {AND,OR,NOT}

d. None of the above

Answer: c

9. Of the following circuits, the one which involves storage is

a. RS Latch

b. mux

c. nand

d. decoder

Answer: a

10.  If the number of address bits in a memory is reduced by 2 and the

addressability is doubled, the size of the memory (i.e., the number of bits stored in the memory)

a. doubles

b. remains unchanged

c. halves

d. increases by 2^(address bits)/addressability

Answer : c

12.  If m is a power of 2, the number of select lines required for an m-input mux is:

a. m

b. 2^m

c. log2 (m)

d. 2*m

Answer: c

13.  For the number A[15:0] = 0110110010001111,  A[14:13] is ______  A[3:2].

a. less than

b. greater than

c. the same as

d . cannot be determined

Answer: c

14. Which of the following conditions is not allowed in an RS latch?

a. R is asserted, S is asserted

b. R is asserted, S is negated

c. R is negated, S is asserted

d. R is negated, S is negated

Answer: a

15. Which of the following pair of gates can form a latch?

a. a pair of cross coupled OR

b. a pair of cross copled AND

c. a pair of cross coupled NAND

d. a cross coupled NAND/OR

Answer: c