Digital Electronics-Digital System Projects Using HDL
Digital Electronics-Digital System Projects Using HDL
21. Which is not a step in strategic planning for HDL development?
- There must be a way to test each piece.
- Each block must fit together to make up the whole system.
- The names of each input and output must be known.
- The exact operation of each block must be thoroughly defined and understood.
22. In the frequency counter, when is the new count stored in the display register?
- After disabling the counter
- When the count buffer is full
- After the sample interval is set
- When the timing and control block has put it there
23. What are two ways to remember the current state of a counter in VHDL?
- With FUNCTIONS and PROCESS
- With counters and timers
- With SIGNAL and VARIABLE
- With bit types
24. In the digital clock project, what type of counter is used to count to 59 seconds?
- MOD-60
- MOD-6
- BCD
- BCD followed by a MOD-6
25. In the keypad application, when all columns are HIGH, the ring counter is enabled and counting, and dav is LOW, what is the status of the d outputs?
- On
- Off
- Hi-Z
- 1011
26. In the frequency counter, what is the function of the Schmitt trigger circuit?
- To reduce input noise
- To condition the input signal
- To convert non-square waveforms
- To provide a usable signal to the display unit
27. List three basic blocks in the digital clock project.
- MOD-60, MOD-12 counters
- MOD-5, MOD-10, MOD-12 counters
- MOD-60, MOD-10 counters
- MOD-6, MOD-12, and MOD-10 counters
28. When designing an HDL digital system, which is the worst mistake one can make?
- Concluding that a fundamental block works perfectly
- Failing to provide proper documentation
- Adding blocks of code prior to testing them
- Overlooking a possible VARIABLE
29. 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 d output to go into its Hi-Z state. On the next rising clock edge, what happens to dav?
- It goes HIGH.
- It goes LOW.
- It goes to Hi-Z.
- It goes to 1111H.
30. For the frequency counter, which is not a control signal from the control and timing block?
- Clear
- Enable
- Reset
- Store