Digital Electronics-Digital Arithmetic Operations and Circuits
Digital Electronics-Digital Arithmetic Operations and Circuits
1. For a 4-bit parallel adder, if the carry-in is connected to a logical HIGH, the result is:
- the same as if the carry-in is tied LOW since the least significant carry-in is ignored.
- that carry-out will always be HIGH.
- a one will be added to the final result.
- the carry-out is ignored.
2. What is the first thing you will need if you are going to use a macrofunction?
- A complicated design project
- An experienced design engineer
- Good documentation
- Experience in HDL
3. Solving –11 + (–2) will yield which two's-complement answer?
- 1110 1101
- 1111 1001
- 1111 0011
- 1110 1001
4. Solve this BCD problem: 0100 + 0110 =
- 00010000BCD
- 00010111BCD
- 00001011BCD
- 00010011BCD
5. What are constants in VHDL code?
- Fixed numbers represented by a name
- Fixed variables used in functions
- Fixed number types
- Constants do not exist in VHDL code.
6. The most commonly used system for representing signed binary numbers is the:
- 2's-complement system.
- 1's-complement system.
- 10's-complement system.
- sign-magnitude system.
7. What is the major difference between half-adders and full-adders?
- Nothing basically; full-adders are made up of two half-adders.
- Full adders can handle double-digit numbers.
- Full adders have a carry input capability.
- Half adders can handle only single-digit numbers.
9. Fast-look-ahead carry circuits found in most 4-bit full-adder circuits:
- determine sign and magnitude
- reduce propagation delay
- add a 1 to complemented inputs
- increase ripple delay
10. The binary subtraction 0 – 0 =
- difference = 0 borrow = 0
- difference = 1 borrow = 0
- difference = 1 borrow = 1
- difference = 0 borrow = 1