1. Draw a logic circuit for the Boolean Function corresponding to a 2-bit Equality Comparator, i.e., that has a value of 1 when two 2-bit numbers A and B are equal, and a 0 otherwise. Also, draw a block diagram of your Equality Comparator. You should be able to extend this (both for the logic circuit and for the block diagram) to a 3-bit Equality Comparator, or in general to an n-bit Equality Comparator, where n is any positive integer.
2. How many selector lines are needed for a 2:1 Multiplexor? For a 3:1 Multiplexor? For a 4:1 Multiplexor? For an n:1 Multiplexor? Draw a truth table and a logic circuit for a 4:1 Multiplexor, spelling out al the logical possibilities (do NOT use "Don't-Care" notation).
3. What do you think a Demultiplexor does? Draw a truth table and a logic diagram for a 1:4 Demultiplexor. How many selector lines does your Demultiplexor have?
4. How many selector lines are needed for a Decoder circuit having 10 output lines? 3 output lines? 5 output lines? n output lines?
5. What do you think an Encoder does? Draw a Truth Table and a logic diagram for a 4:2 Encoder with active-high inputs.
6. Draw the symbol for a Tri-Sate Buffer, and the electronic CMOS transistor circuit for this device.
7. Examine the circuit diagram shown in Figure 11.7 of Bebop to the Boolean Boogie. To which device of the five described so far in this question set does this circuit most closely correspond?
8. Draw a diagram of the logic circuit of an SR Latch with active-high set and reset. Do the same for active-low set and reset. Explain how each circuit works.
9. Draw a logic circuit diagram to show how you would add on logic elements or make additional connections to the front end of an SR Latch to convert it to a JK Latch. To a D Latch. To a T Latch.
10. Draw a diagram of the logic circuit of an active-high enabled D Latch. Explain how the circuit works.
11. Draw diagrams to explain the difference between a Moore Machine and a Mealy Machine.
12. Define each of the following terms as it is used to describe some aspect of the production of digital integrated circuits:

Wafer

Lithography

Mask

Step-and-Repeat Process

Substrate

Silicon Dioxide (What is another name for Silicon Dioxide?

Organic Resist

Etching

Poly

Metallization layer

Aluminum pads

Overglassing

Wafer Probing

Yield

Die

Lead Frame

Wire bonding

Encapsulation

Die stacking

13. Describe and explain the difference between Positive Resist and Negative Resist processes.
14. What is the difference between Optical Lithography, X-Ray Lithography, and Electron-Beam Lithography? Which technique is the least expensive? Which offers the most promise in terms of reduction of size of circuit elements?
15. What does each of the following acronyms or abbreviations stand for in the context of electronic circuit design?

BJT

TTL

ECL

MOS FET

CMOS

NMOS

PMOS

GaAs

BiCMOS

16. Rewrite the following list of terms in rank order (a) from slowest to fastest; (b) from lowest power consumption to highest.

BJT

CMOS

ECL

TTL

GaAs

17. Why is BiCMOS useful?
18. Indicate (a) what does each of the following acronyms stand for, and (b) briefly describe the device.

SRAM

DRAM

ROM

PROM

EPROM

EEPROM

19. What is the difference between SRAM and DRAM?
20. What is the difference between volatile and non-volatile memory?
21. Indicate (a) which of the following types of memory are volatile, and which are non-volatile; also, (b) which can be readily overwritten and which cannot:

Magnetic Core memory

Magnetic Drum memory

SRAM

DRAM

ROM

PROM

EPROM

EEPROM

"Flash Memory"

Floppy Disk

Hard Disk

CD-ROM

DVD

22. Define each of the following terms with respect to computer memory:

Cell

Word

Width

Depth

23. Describe the relationship between width of the memory and the number of lines in the data bus.
24. Describe the relationship between depth of the memory and the number of lines in the address bus.
25. What does each of the following acronyms stand for?

PAL

PLA

PLD

FPGA

ASIC

26. Why are PLDs and ASICs useful?

Answers to Selected Questions:

Last updated 03 Jan 2000