Digital Electronics-Describing Logic Circuits
Digital Electronics-Describing Logic Circuits
1. The format used to present the logic output for the various combinations of logic inputs to a gate is called a(n):
- truth table.
- input logic function.
- Boolean constant.
- Boolean variable.
2. What is the basic difference between AHDL and VHDL?
- ADHL is used in all PLD's.
- VHDL is used in all PLD's.
- ADHL is proprietary.
- VHDL is proprietary.
3. small circle on the output of a logic gate is used to represent the:
- Comparator operation.
- OR operation.
- NOT operation.
- AND operation.
4. In VHDL, the mode of a port does not define:
- an input.
- an output.
- both an input and an output.
- the TYPE of the bit.
5. Which of the following equations would accurately describe a 4-input OR gate when A = 1, B = 1, C = 0, and D = 0?
- 1 + 1 + 0 + 0 = 1
- 1 + 1 + 0 + 0 = 01
- 1 + 1 + 0 + 0 = 0
- 1 + 1 + 0 + 0 = 00
6. Which of the examples below expresses the distributive law?
- (A + B) + C = A + (B + C)
- A(B + C) = AB + AC
- A + (B + C) = AB + AC
- A(BC) = (AB) + C
7. How are the statements between BEGIN and END not evaluated in VHDL?
- Constantly
- Simultaneously
- Concurrently
- Sequentially
8. A NOR gate with one HIGH input and one LOW input:
- will output a HIGH
- functions as an AND
- will not function
- will output a LOW
9. A NAND gate has:
- active-LOW inputs and an active-HIGH output.
- active-LOW inputs and an active-LOW output.
- active-HIGH inputs and an active-HIGH output.
- active-HIGH inputs and an active-LOW output.
10. The logic gate that will have HIGH or "1" at its output when any one of its inputs is HIGH is a(n):
- NOR gate
- OR gate
- AND gate
- NOT operation