Digital Electronics- MSI Logic Circuits
Digital Electronics- MSI Logic Circuits
1. Which statement below best describes the function of a decoder?
- A decoder will convert a decimal number into the proper binary equivalent.
- A decoder will convert a binary number into a specific output representing a particular character or digit.
- Decoders are used to prevent improper operation of digital systems.
- Decoders are special ICs that are used to make it possible for one brand of computer to talk to another.
2. One can safely state that the output lines for a demultiplexer are under the direct control of the:
- input data select lines.
- the internal AND gates.
- the internal OR gate.
- Input data line.
3. A 16-input multiplexer is to be used to perform parallel-to-serial data conversion. Which of the following counters would be required to provide the data select inputs?
- MOD 8
- MOD 16
- MOD 4
- MOD 2
4. A breadboard-circuit design using a BCD-to-decimal decoder has a problem wherein the operation of the system is erratic. The technician uses his scope to examine the waveforms throughout the system and doesn't really see any problems. While he's scratching his head, what helpful advice can you offer him as to what might be wrong and what to do to correct the problem?
- The decoder is thermally intermittent; replace it.
- There is probably a bad connection on the wire wrap protoboard; recheck the wiring.
- Glitches are probably the culprit; strobe the decoder.
- The decoder is thermally intermittent and must be replaced; or there is probably a bad connection on the wire wrap protoboard, and the wiring must be rechecked.
5. How is the number one (1) indicated on the outputs of a 7447 BCD-to-seven-segment code converter?
- Segment a is active.
- Segment b is active.
- Segments a and b are active.
- Segments b and c are active.
6. The IEEE/ANSI symbol for a decoder has the internal designation bcd/dec. This means the decoder is a:
- decimal-to-BCD decoder with ten inputs and four outputs.
- BCD-to-decimal decoder with ten inputs and four outputs.
- decimal-to-BCD decoder with four inputs and ten outputs.
- BCD-to-decimal decoder with four inputs and ten outputs.
7. Multiplexing of digital signals is usually required when:
- moving data internally within a microprocessor.
- moving data between memory and storage registers in a microprocessor.
- moving data over long distance transmission lines.
- moving data internally within a microprocessor or between memory and storage registers.
8. Which is the decimal number for the BCD number, 10110110?
- 182
- 36
- 116
- 10110110 is not a valid BCD number.
9. In an AHDL BCD to binary code converter, how is multiplication by 10 accomplished?
- By using the shifting of bits
- By using the library multiplication function
- By using integer types
- By using the multiplication operator
10. What is the HDL key issue in the design of the MUX and DEMUX?
- Having the MUX and DEMUX part of the library
- Using the case statement in the process
- Describing the functions
- Assigning signals under certain conditions