In the name of ALLAH, the most beneficient, the most merciful

Digital Logic Design (CS302)

Multiple Choice Questions (MCQs)

Objective Questions

  1. Subtractors also have output to check if 1 has been ________.

    1. Primed
    2. Shifted
    3. Complemented
    4. Borrowed
  2. The S-R latch has two inputs, therefore ________ different combinations of inputs can be applied to control the operation of the S-R latch.

    1. two
    2. four
    3. eight
    4. sixteen
  3. A multiplexer with a register circuit converts

    1. Serial data to parallel
    2. Parallel data to serial
    3. Serial data to serial
    4. Parallel data to parallel
  4. The ________ input overrides the ________ input.

    1. Asynchronous, synchronous
    2. Synchronous, asynchronous
    3. Preset input (PRE), Clear input (CLR)
    4. Clear input (CLR), Preset input (PRE)
  5. If two numbers in BCD representation generate an invalid BCD number then the binary ________ is added to the result.

    1. 1001
    2. 0110
    3. 1111
    4. 1100
  6. The ________ gate and ________ gate implementation connected at the B input of the 4-bit Adder is used to allow Complemented or Un-Complemented B input to be connected to the Adder input.

    1. AND, NOR
    2. AND, NOT
    3. AND, OR
    4. XOR, NAND
  7. The Adjacent 1s Detector accepts 4-bit inputs. If ________ adjacents 1s are detected in the input, the output is set to high.

    1. 2
    2. 4
    3. 1
    4. 0
  8. PLDs have In-System Programming (ISP) capability that allows the ________ to be programmed after they have been installed on a circuit board.

    1. PLAs
    2. PALs
    3. PLDs
    4. EPROM
  9. A SOP expression can be implemented by an ________ combination of gates.

    1. OR-XOR
    2. AND-NAND
    3. AND-OR
    4. XOR-NOR
  10. A 4-bit binary up/down counter is in the binary state of zero. The next state in the DOWN mode is:

    1. 0001
    2. 1000
    3. 1110
    4. 1111
  11. In the keyboard encoder, how many times per second does the ring counter scan the key board?

    1. 600 scans/second
    2. 625 scans/second
    3. 650 scans/second
    4. 700 scans/second
  12. The next state table for REQ1, FLOOR1 and OPEN inputs indicates that the ________ can be pressed at any time either on the first floor or the second floor in elevator.

    1. REQ0
    2. OPEN
    3. REQ1
    4. FLOOR1
  13. The Transition table is very similar to the ________ table.

    1. Truth
    2. State
    3. Transition
    4. None of the given
  14. Which of the following is a volatile memory?

    1. PROM
    2. DRAM
    3. EPROM
    4. EEPROM
  15. Flash memory Operation are classified into ________ different operation.

    1. Two
    2. Three
    3. Four
    4. Five
  16. The FAST Model Page Access allows ________ memory read and access times when reading successive data values stored in consecutive locations on the same row.

    1. Slow
    2. Faster
    3. Medium
    4. Modern
  17. An Asynchronous Down-counter is implemented (Using J-K flip-flop) by connecting ________.

    1. Q output of all flip-flops to clock input of next flip-flops
    2. Q' output of all flip-flops to clock input of next flip-flops
    3. Q output of all flip-flops to J input of next flip-flops
    4. Q' output of all flip-flops to K input of next flip-flops
  18. Cin is part of ________ Adder.

    1. Half
    2. Full
    3. Single
    4. Double
  19. The ROM used by a computer is relatively ________ as it stores few byres of code used to Boot the Computer system on power up.

    1. Small
    2. Large
    3. Heavy
    4. High
  20. Implementing the Adjacent 1s detector circuit directly from the function table based on the SOP form requires ________ gates for the 8 product terms (minterms) with an 8-input OR gate.

    1. 8 OR
    2. 8 AND
    3. 8 XOR
    4. 8 NOR
  21. In NAND based S-R latch, output of each ________ gate is connected to the input of the other ________ gate.

    1. NOR, NAND
    2. NAND, NOR
    3. NOR, NOR
    4. NAND, NAND
  22. Which of the following Output Equations determines the output of the State Machine?

    1. MIN = Q0Q1
    2. MAX = Q0Q1EN
    3. MIN = Q0Q1EN
    4. MAX = Q1EN
  23. Consider the sum of weight method for converting decimal into binary value, ________ is the highest weight for 411.

    1. 64
    2. 128
    3. 256
    4. 512
  24. GAL can be reprogrammed as instead of fuses E2CMOS logic is used which can be programmed to connect a ________ with a ________.

    1. column, row
    2. row, column
    3. column, column
    4. row, row
  25. The AND Gate performs a logical ________ function.

    1. Addition
    2. Substraction
    3. Multiplication
    4. Division
  26. The Static Ram (SRAM) is non-volatile and is not a ________ density memory as a latch is required to store a single bit of information.

    1. Low
    2. High
    3. Medium
    4. Hot
  27. Canonical form is a unique way of representing ________.

    1. SOP
    2. Minterm
    3. Boolean Expression
    4. POS
  28. For a down counter that counts from (111 to 000), if current state is "101" the next state will be ________.

    1. 111
    2. 110
    3. 010
    4. None of the given
  29. The 64-cell array organized as 8 x 8 cell array is considered

    1. as an 64 byte memory
    2. as a 16 byte memory
    3. as an 8 byte memory
    4. as an 4 byte memory
  30. ________ Counters as the name indicates are not triggered simultaneously.

    1. Asynchronous
    2. Synchronous
    3. Positive-Edge triggered
    4. Negative-Edge triggered
  31. A NOR based S-R latch is implemented using ________ gates instead of ________ gates.

    1. XOR, NAND
    2. NOR, XOR
    3. NOR, NAND
    4. OR, XOR
  32. The CONSTATE.CLK = Clock is used to indicate that the ________ state variables change on a clock transition.

    1. CONSTATE
    2. FLOOR
    3. MOTION
    4. OPEN
  33. The Test Vector definition defines the test vectors for all the three counter inputs and ________ counter output/outputs.

    1. One
    2. Two
    3. Three
    4. Four
  34. If the number of samples that are collected is reduced by half, the reconstructed signal will be ________ from/to the original.

    1. Different
    2. Same
    3. Equal
    4. Opposite
  35. For a Standard SOP expression, a ________ is placed in the cell corresponding to the product term (Minterm) present in the expression.

    1. 0
    2. 1
    3. x (don't care condition)
    4. Any of given option depending on SOP term
  36. The output of a NAND gate is ________ when all the inputs are one.

    1. Zero
    2. One
    3. Available
    4. Not available
  37. A decade counter can be implemented by truncating the counting sequence of a MOD-20 counter.

    1. True
    2. False
  38. The NOR logic gate is the same as the operation of the ________ gate with an inverter connected to the output.

    1. AND
    2. NAND
    3. OR
    4. NOT
  39. 8-bit parallel data can be converted into serial data by using ________ multiplexer.

    1. 4-to-2
    2. 8-to-1
    3. 4-to-4
    4. 8-to-4
  40. In case of cascading Integrated Circuit counters, the enable inputs and RCO of the Integrated Circuit counters allow cascading of multiple counters together.

    1. True
    2. False
  41. The terminal count of a 4-bit binary counter in the UP mode is ________.

    1. 1100
    2. 0011
    3. 1111
    4. 0000
  42. In memory write cycle, the time for which the WE signal remains active is known as the ________.

    1. Write address setup
    2. Write pulse width
    3. Write delay width
    4. Write data time
  43. Two signals ________ and ________ provide the timing inputs to the State Machine.

    1. NSSR and EWSR
    2. LTIME and STIME
    3. PTIME and QTIME
    4. NSGrn and NSYel
  44. Consider A=1, B=0, C=1. A, B and C represent the input of three bit NAND gate, the output of the NAND gate will be ________.

    1. Zero
    2. One
    3. Undefined
    4. No output as input is invalid
  45. Why demultiplexer is called a data distributor?

    1. The input will be distributed to one of the outputs
    2. The input will be selected for the output
    3. The output will be distributed to one of the inputs
    4. Single input to Single Output
  46. The n flip-flops store ________ states.

    1. 1
    2. 2^n
    3. 0
    4. 2^(n+1)
  47. The outputs of SR latches in elevator state machine are feed back to the ________ gate array for connection to the D-flipflops.

    1. NOT
    2. AND
    3. OR
    4. XOR
  48. Memory is arranged in ________.

    1. linear fashion
    2. two-dimensional manner
    3. three-dimensional manner
    4. random fashion
  49. Adding two octal numbers "36" and "71" result in ________.

    1. 213
    2. 123
    3. 127
    4. 345
  50. If the voltage drop across the active load is 0 volts due to absence of current the comparator output is a ________.

    1. 0
    2. 1
  51. In DRAM read cycle R /W- signal is activated to read data which is made available on the ________ data line.

    1. D(IN)
    2. D(OUT)
    3. D(AB)
    4. D(INT)
  52. The 74HC163 is a 4-bit Synchronous counter, it has ________ data output pins.

    1. 2
    2. 4
    3. 6
    4. 8
  53. Two types of memories namely the first in-first out (FIFO) memory and last in first out (LIFO) are implemented using ________.

    1. Shift Registers
    2. Circular Buffers
    3. Ring Buffers
    4. Reduce Registers
  54. A 3-variable karnaugh map has

    1. eight cells
    2. three cells
    3. sixteen cells
    4. four cells
  55. PALs tend to execute ________ logic.

    1. SPD
    2. SOP
    3. SAC
    4. SAP
  56. The normal data inputs to a flip-flop (D, S and R, J and K, T) are referred to as ________ inputs.

    1. Sequential
    2. Asynchronous
    3. Synchronous
    4. Combinational
  57. The domain of the expression AB'CD + AB' + C'D + B is

    1. A and D
    2. B only
    3. A, B, C and D
    4. None of the given
  58. As data values are written or read from the RAM Stack Pointer Register increments or decrements its contents always pointing to the stack ________.

    1. Bottom
    2. Top
    3. Down
    4. Vertex
  59. Which one flip-flop has an invalid output state?

    1. T
    2. JK
    3. SR
    4. D
  60. ________ is used when the output is connected back to the input of the PAL or if the output pin is used as an input only.

    1. Combinational Input/Output
    2. Combinational Output
    3. Combinational Input
    4. Programmable polarity
  61. Demorgan's two theorems prove the equivalency of the NAND and ________ gates and the NOR and ________ gates respectively.

    1. Negative-OR, Negative-AND
    2. Negative-AND, Positive-OR
    3. Positive-OR, Negative-AND
    4. Positive-OR, Positive-AND
  62. The maximum value, represented by a single hexadecimal digit is ________.

    1. "E"
    2. "F"
    3. "G"
    4. "H"
  63. In distributed mode, for a 1024 x 1024 DRAM memory and a refresh cycle of 8 msec, each of the 1024 rows has to be refreshed in ________ when Distributed refresh is used.

    1. 4.8 microsec
    2. 5.9 microsec
    3. 7.8 microsec
    4. 5.5 microsec
  64. Select the mode of programming in which GAL16V8 can be programmed:

    1. Simple Mode
    2. Complex Mode
    3. Registered Mode
    4. All of the given
  65. Divide-by-32 counter can be achieved by using

    1. Flip-Flop and DIV 10
    2. Flip-Flop and DIV 16
    3. Flip-Flop and DIV 32
    4. DIV 16 and DIV 32
  66. Which signal must remain valid in memory write cycle after data is applied at the data input lines and must remain valid for a minimum time duration tWD?

    1. -CS
    2. -WE
    3. W
    4. OE
  67. The Synchronous SRAM also has a Burst feature which allows the Synchronous SRAM to read or write up to ________ location(s) using a single address.

    1. One
    2. Two
    3. Three
    4. Four
  68. UVERPROM is stands for

    1. Ultra-Variant
    2. Ultra-Vibrant
    3. Ultra-Voilet
    4. Ultra-Visible
  69. The ABEL Input file can use a ________ instead of the equation to specify the Boolean expressions.

    1. Truth Table
    2. State Diagram
    3. Karnaugh Map
    4. Logic Circuit
  70. Implementation of Latch is required almost ________ transistor.

    1. Two
    2. Four
    3. Six
    4. Eight
  71. When the transmission line is idle in an asynchronous transmission

    1. It is set to logic low
    2. It is set to logic high
    3. It remains in previous state
    4. State of transmission line is not used to start transmission
  72. Implementation of the FIFO buffer in ________ is usually takes the form of a circular buffer.

    1. RAM
    2. ROM
    3. PPROM
    4. Flash Memory
  73. You have to choose suitable option when your timer will reset by considering this given code:
    TRSTATE.CLK = clk;
    TMRST: = (TRSTATE = = NSY2) # (TRSTATE = = EWY2);

    1. NSY2 or EWY2
    2. NSSR or TMRST
    3. EWSR or NSRED
    4. EWRed or EWYel