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This section includes 96 Mcqs, each offering curated multiple-choice questions to sharpen your Digital Electronics knowledge and support exam preparation. Choose a topic below to get started.
1. |
In the keypad encoder, the ring counter is implemented using ________ that responds to the input. |
A. | SIGNAL |
B. | FUNCTION |
C. | CASE |
D. | PROCESS |
Answer» E. | |
2. |
In the keypad HDL encoder, the bit array represents a tristate buffer. |
A. | True |
B. | False |
Answer» B. False | |
3. |
In the VHDL code of the stepper motor, the outputs are bit_vector type because they are binary bit patterns. |
A. | True |
B. | False |
Answer» B. False | |
4. |
In the keypad application, when all columns are HIGH, the ring counter is enabled and counting, and is LOW, what is the status of the outputs? |
A. | On |
B. | Off |
C. | Hi-Z |
D. | 1011 |
Answer» D. 1011 | |
5. |
In the keypad application, just after the 4 ms mark the simulation imitates the release of the key by changing the column value back to F hex, which causes the output to go into its Hi-Z state. On the next rising clock edge, what happens to ? |
A. | It goes HIGH. |
B. | It goes LOW. |
C. | It goes to Hi-Z. |
D. | It goes to 1111H. |
Answer» C. It goes to Hi-Z. | |
6. |
The full-step sequence always has two coils of the stepper motor energized in any state of the sequence and typically causes 30° of shaft rotation per step. |
A. | True |
B. | False |
Answer» C. | |
7. |
The major blocks of the frequency counter are the counter, ________, decoder/display, and the timing and control unit. |
A. | signal prescaler |
B. | control inputs |
C. | signal generator |
D. | display register |
Answer» E. | |
8. |
In the keypad encoder, the ________ activate(s) the freeze bit only when one column is low. |
A. | NAND columns |
B. | CASE structure |
C. | freeze function |
D. | BCD counter |
Answer» C. freeze function | |
9. |
One aspect of project planning and management is the selection of ________ that will best fit the application. |
A. | hardware platform |
B. | software |
C. | personnel |
D. | time |
Answer» B. software | |
10. |
In the keypad HDL encoder, as long as all columns are high the ring counter is enabled and counting. |
A. | 1 |
B. | |
Answer» B. | |
11. |
A very critical dimension in project management is the time your boss will give you to complete the HDL project. |
A. | 1 |
B. | |
Answer» B. | |
12. |
The step rate of the simulation of a stepper motor is probably ________ the actual stepper motor. |
A. | slower than |
B. | more than |
C. | almost the same as |
D. | exactly the same as |
Answer» B. more than | |
13. |
In the digital clock project, the ENT input and RCO output can be used for synchronous counter cascading. |
A. | 1 |
B. | |
Answer» B. | |
14. |
The direct drive mode of a stepper motor allows for less control by the operator. |
A. | 1 |
B. | |
Answer» C. | |
15. |
In the keypad HDL encoder, the ts bit array represents a tristate buffer. |
A. | 1 |
B. | |
Answer» B. | |
16. |
In the frequency counter, the control clock is derived from the ________ by frequency dividers controlled in the control and timing block. |
A. | BCD counters |
B. | system clock signal |
C. | display register |
D. | decoder/display |
Answer» C. display register | |
17. |
In the stepper motor, the half-step sequence is used when ________. |
A. | less torque is needed |
B. | larger steps are desired |
C. | smaller steps are desirable |
D. | more torque is needed |
Answer» D. more torque is needed | |
18. |
A frequency counter is a circuit that can measure and display the frequency of a signal. |
A. | 1 |
B. | |
Answer» B. | |
19. |
In the keypad HDL encoder, the data signal is used to combine the row and column encoder data to make a 4-bit value representing the key that was pressed. |
A. | 1 |
B. | |
Answer» B. | |
20. |
In HDL when a circuit is simulated on a computer, the designer must create all the different scenarios that will be experienced by the actual circuit and must also know the proper response to those inputs. |
A. | 1 |
B. | |
Answer» B. | |
21. |
In the digital clock project, a 60 pps input is transformed into a 1 pps timing signal. The block is called ________. |
A. | a BCD counter |
B. | a MOD-60 counter |
C. | frequency divider |
D. | frequency prescaling |
Answer» E. | |
22. |
Using one case construct inside another is known as ________. |
A. | doping |
B. | functioning |
C. | freezing |
D. | nesting |
Answer» E. | |
23. |
One of the first steps in small-project management is to determine ________. |
A. | how many devices are controlled by the outputs |
B. | a way to test each block |
C. | if each block fits together |
D. | how each block works |
Answer» B. a way to test each block | |
24. |
In the digital clock project HDL, the 1 pps signal is used as a synchronous clock for all of the counters' stages, which are synchronously cascaded. |
A. | 1 |
B. | |
Answer» B. | |
25. |
The wave-drive sequence of a stepper motor has more torque and operates more smoothly than the full-step sequence at moderate speeds. |
A. | 1 |
B. | |
Answer» C. | |
26. |
In the keypad HDL encoder, the freeze bit detects when a key is released. |
A. | 1 |
B. | |
Answer» C. | |
27. |
VARIABLES are considered to be updated ________ within a sequence of statements in a PROCESS, whereas SIGNALS referred to in a PROCESS are updated when the PROCESS ________. |
A. | once, starts |
B. | immediately, suspends |
C. | twice, ends |
D. | never, starts |
Answer» C. twice, ends | |
28. |
In the keypad encoder, just after the 4 ms mark, the simulation initiates the release of the key by changing the column value to ________, which causes the d output to go into its Hi-Z state. |
A. | 0 hex |
B. | 4 hex |
C. | 8 hex |
D. | F hex |
Answer» E. | |
29. |
The full-step sequence of a stepper motor always has two coils energized in any state of the sequence and typically causes ________ of shaft rotation per step. |
A. | 5° |
B. | 10° |
C. | 15° |
D. | 20° |
Answer» D. 20¬∞ | |
30. |
In the digital clock project, the AHDL block codes are connected using graphic design files. |
A. | 1 |
B. | |
Answer» B. | |
31. |
In the keypad HDL encoder, NANDing of the columns is used to activate the freeze bit. |
A. | 1 |
B. | |
Answer» C. | |
32. |
In the digital clock project, when it is 11:59:59, AND gate 1 detects that the tens of hours is 1 and the enable input is active. On the next clock pulse the AM/PM flip-flop will ________. |
A. | set |
B. | reset |
C. | toggle |
D. | clear |
Answer» D. clear | |
33. |
The stepper motor HDL will ignore its counter inputs and pass control inputs directly to the output when set in mode ________. |
A. | 1 |
B. | 2 |
C. | 3 |
D. | 4 |
Answer» B. 2 | |
34. |
In the frequency counter, a pulse shaper block is needed to ensure that the unknown signal, whose frequency is to be measured, will be compatible with the clock input for the counter block. |
A. | 1 |
B. | |
Answer» B. | |
35. |
In the digital clock project, the 60 Hz signal is sent through a Schmitt-trigger circuit to produce sine wave pulses at the rate of 60 pps. |
A. | 1 |
B. | |
Answer» C. | |
36. |
One CASE construct inside another CASE construct is called a do-loop. |
A. | 1 |
B. | |
Answer» C. | |
37. |
In the frequency counter, the length of time for the ________ to be enabled can be selected with the range select input. |
A. | display register |
B. | frequency prescaler |
C. | BCD counter |
D. | signal generator |
Answer» D. signal generator | |
38. |
In a real project, the first step of definition often involves some ________ on the part of the project manager. |
A. | time |
B. | skill |
C. | research |
D. | management |
Answer» D. management | |
39. |
In the digital clock design, the hours section is different from the seconds and minutes section in that it never goes to ________. |
A. | the 0 state |
B. | 13 |
C. | the ring counter |
D. | the BCD counter |
Answer» B. 13 | |
40. |
Depending on the ________ the IC is in, the output of the stepper motor HDL will respond to each pulse by changing state. |
A. | mode |
B. | make |
C. | input |
D. | output |
Answer» B. make | |
41. |
In the frequency counter, the pulse width of the enable signal is very critical for taking an accurate frequency measurement. |
A. | 1 |
B. | |
Answer» B. | |
42. |
In the keypad HDL encoder, after releasing a key the ring counter resumes its counting sequence. |
A. | 1 |
B. | |
Answer» B. | |
43. |
The full-step sequence always has two coils of the stepper motor energized in any state of the sequence and typically causes 30° of shaft rotation per step. |
A. | 1 |
B. | |
Answer» C. | |
44. |
In the keypad encoder, the ________ detects when a key is pressed. |
A. | ring counter |
B. | MOD-6 counter |
C. | BCD counter |
D. | freeze bit |
Answer» E. | |
45. |
Each ________, starting at the simplest level, should be built in HDL. |
A. | subsystem |
B. | block |
C. | circuit |
D. | function |
Answer» B. block | |
46. |
In the VHDL code of the stepper motor, the cout outputs are bit_vector type because they are binary bit patterns. |
A. | 1 |
B. | |
Answer» B. | |
47. |
What must a stepper motor HDL application include? |
A. | Variables and processes |
B. | Types and bits |
C. | Counters and decoders |
D. | Sequencers and multiplexers |
Answer» D. Sequencers and multiplexers | |
48. |
Which is not a step used to define the scope of an HDL project? |
A. | Are the inputs and outputs active HIGH or active LOW? |
B. | A clear vision of how to make each block work |
C. | What are the speed requirements? |
D. | How many bits of data are needed? |
Answer» C. What are the speed requirements? | |
49. |
In the digital clock project, when it is 11:59:59, AND gate 1 detects that the tens of hours is 1 and the edge trigger clock moves the display to 12:00:00. |
A. | 1 |
B. | |
C. | 1 |
D. | |
Answer» C. 1 | |
50. |
When coming up with a strategy for dividing the overall project into manageable-size pieces one must ________. |
A. | name each input and output |
B. | fully understand how the device should operate |
C. | define successful completion of the project |
D. | know the nature of all the signals that interconnect all the pieces |
Answer» E. | |